Posts Tagged ‘chronograph’
Benjamin Rogue ePCP: Part 5
by Tom Gaylord, a.k.a. B.B. Pelletier
The new Rogue is simpler, more tractable.
Think of this report as a bonus. I thought I was finished with the Rogue after Part 4, but then Seth Rowland — the man who organizes the Malvern, AR, airgun show and also provides big bore airgunners with swaged and cast lead bullets — contacted me, saying that he had been following the series. He told me he had a couple different bullet designs, some that he swages and can control the weight and length of the bullet. He wondered if I wanted to test the rifle with some more bullets — this time from a source other than Crosman/Benjamin. He had no idea whether any of the bullets would work in the rifle, but he did know they were large enough to fit the bore well.
I thought, what the heck — let’s give them a try. I contacted Crosman to get an extension to the loan of the new Rogue. Since this gives me one more day at the range with the rifle, who am I to complain?
Seth sent me 5 bullets in all. They range from 89 grains to 137 grain, so the spectrum is covered pretty well. You may remember that I found the Rogue to shoot best with lighter-weight bullets, which is why Seth sent me these particular ones.
From the left, we have an 89-grain swaged bullet, 119-grain swaged bullet, 128-grain cast bullet, 130-grain cast bullet and a 137-grain swaged bullet.
At the range
The day was perfect. The wind was a light breeze that caused no problems at the 50-yard range. I took each bullet in succession, starting with the lightest weight and progressing to the heaviest. Each bullet shot a 5-shot group at 50 yards. The electronic valve setting was on Light for the bullet and Medium for the power. I figured that if any bullets showed promise, I could return and test them on High power later.
The 89-grain bullet had only fair accuracy and strung its shots vertically in a group measuring just under 4 inches. It was too early in the test to know very much, so I moved on to the 119-grain swaged bullet. It opened up to just over 5 inches, telling me this also was not a bullet for the Rogue. Since it was also swaged, I wondered if that was causing some kind of problem.
The next bullet was the 128-grain cast bullet. Five of those landed in 1.483 inches, looking very nice, indeed. That’s certainly minute-of-coyote or fox at 50 yards…and on out to, perhaps, 75 yards. The cast bullet looks like a design for either a black powder cartridge or a pistol. It was the best group I got so far.
Five shots with the 128-grain cast bullet on Medium power produced this group, which is under 1.5 inches.
Next came the 130-grain cast lead bullet, and it didn’t even land on the target paper. Since I back my targets with a 2-foot by 4-foot target paper to catch strays like this, and since I failed to catch this bullet anywhere, I stopped trying after three shots. Let’s call the 130-grain bullet a non-starter for the Rogue.
The last bullet was a 137-grain swaged design that also failed to make a hole on the large backer paper after 3 shots. It was out, as well.
So far
To this point, it looks like the 128-grain cast lead bullet is the one to spend time with. I chronographed it and found it averaged 699 f.p.s. on Medium power (138.91 foot-pounds) and 731 f.p.s. on High power (151.91 foot-pounds). On Medium power with a fresh 3,000 psi fill, the gun’s status panel tells me there are 11 shots at the beginning. But the status panel number of shots that remain decreases faster than the actual number of shots. Although it says there are 11 shots, there are really 6 or 7 shots before it’s time to fill again.
On High power, the gun starts out with 3 shots on the panel — but I found that I got only 2 shots before the gun wanted to be refilled. A third shot was possible, and I took one just to see where the bullet went. It stayed within the group, though on High power the group is larger than on Medium.
Five 128-grain bullets on High power opened up to 2.847 inches. The shot at the right is after a refill of air.
What do we know?
First, we know that cast bullets with grease grooves seem to shoot better in our Rogue than swaged bullets. At least, there’s an inclination in that direction.
Next, we know that the 128-grain bullet did best in this rifle. If further testing was to be done, that’s the bullet I would concentrate on. I went back and reviewed the performance with all the other bullets that were tested in the past, and this one looks quite similar to the Benjamin Pursuit 127-grain flat-nosed bullet. What that means is that it’s possible to cast your own bullets or to buy them from a source that casts them, as they’re going to perform similarly to the best bullets in this rifle. Both these bullets out-shot the 145-grain Nosler Ballistic Tips that are also good in the Rogue.
We also know that shooting on Medium power conserves air longer than High power, and the slight loss of velocity is inconsequential. Of course, I’d like to play with this bullet even more, shooting it with the control panel set to Heavy weight and shooting it on Discharge, as well as directly controlling the valve dwell time. From just what we have seen in today’s test, I would say this is a bullet to beat.
Remember — this was a test of unknown bullets to see if any were worth testing further. If I owned a Rogue, I would stock up on this 128-grain bullet and play with it more because I think this may be the best overall design for the rifle.
Thanks to Seth Rowland (sethrowland@att.net) for providing these bullets to test. He makes other calibers and will work with you to find the best bullet for your rifle.
Bottom line for the Rogue
The Rogue has its detractors — those who feel that it’s to advanced and expensive to be practical in the field. But those people disregard the fact that this rifle shoots as well as almost all other big bores of quality.
All I’ve done in this 5-part test is show you how it performs. The rest is up to you.
Benjamin Rogue ePCP: Part 4
by Tom Gaylord, a.k.a. B.B. Pelletier
The new Rogue is simpler, more tractable.
After the last report, I spoke to Dennis Quackenbush about how the new Rogue I was testing. I explained that while it shot well with Benjamin bullets, it didn’t seem to group with cast bullets obtained from other sources. He first suggested that I try the old .38-caliber 200-grain lead bullet that we know as a police round here in the U.S.; but in the UK it was their substitute for the old .455 round. When they downsized their WWI service revolver to reduce the recoil, they substituted the 200-grain .38-cal. bullet for the much larger .455-caliber man-stopper they had in WWI. Unfortunately, they also knocked about 9 oz. off the weight of the revolver at the same time, with the result that the new cartridge and revolver kicked just about the same as the one it replaced. It was easier to carry, of course, and that’s always a consideration, but it wasn’t the man-stopper the older bullet had been.
I told Dennis that the heavier I went, the more the Rogue didn’t like the bullet, so he then came up with a different idea. He suggested I try a bullet with a different balance. He asked me if I had tried the rifle with a 148-grain .357-caliber wadcutter, which of course I hadn’t. Some wadcutter bullets have a hollow base that obturates when the cartridge explodes, thus filling the bore and sealing all gasses behind.
The .357 wadcutter bullet weighs 148 grains and has a hollow base similar to a diabolo pellet. That pushes the weight forward and helps stabilize the bullet in flight. This lead isn’t oxidizing. That white powder is the dry lubricant that has been applied to the bullet after casting or swaging. Notice the lack of conventional grease grooves.
The wadcutters were the first non-Benjamin bullets to perform well in the Rogue. They fed well, and they also shot to the same point of aim as both of the Benjamin bullets. This proves that a Rogue owner can cast his own bullets for the rifle and save a lot of money. In fact, with a Shoebox Compressor and casting your own bullets, the Rogue would be cheaper to shoot than a smallbore pellet rifle!
Low on air: What can I do?
When I shot the wadcutter bullets for accuracy, I knew my carbon fiber tank was running low. I still had to chronograph all the bullets at both power settings and wanted to save some air for that, so I decided to try something different during this group. Five bullets were fired with the rifle set to heavy bullets and medium power. That ran the gun out of a charge of air. The display panel said there were no shots remaining at that setting. I changed the power setting to discharge, which holds the valve open twice as long as normal. I then fired two more shots on the discharge setting just to see what would happen. I labeled each hole on the target, so you can see where every shot went.
The five bullets fired on medium power grouped in about 2-3/4 inches at 50 yards. Each shot is numbered. Then the two discharge shots hit lower and to the left. Interesting that you can actually get more shots on a fill than the status panel indicates!
Velocity
Now, it was time to test the velocity of all the bullets that were accurate in the Rogue. This exercise used up the remaining air in my tank, thus ending the day at the range.
Nosler 145-grain Ballistic Tip
The first bullet we’ll test is the 145-grain Nosler Ballistic Tip bullet that’s the best general bullet for the Rogue. On high power, the bullet averaged 774 f.p.s., with a range from 766 to 781 f.p.s. At the average velocity, the rifle generated 192.92 foot-pounds of muzzle energy.
On medium power, this bullet averaged 751 f.p.s. and ranged from 741 to 760 f.p.s. At the average velocity, the bullet generates 181.64 foot-pounds of energy. That’s pretty remarkable, because that’s also a good place to keep the power for the extra shots it provides.
Benjamin Pursuit 158-grain bullet
The Benjamin Pursuit 158-grain round nose bullet was tested next. It was tested in the last accuracy test and proved to be acceptable at 50 yards. On high power, this bullet averaged 741 f.p.s., with a velocity spread that ranged from 735 to 752 f.p.s. At the average velocity, it generates 192.69 foot-pounds of muzzle energy. The Nosler Ballistic Tip reigns supreme for power in the Rogue by a razor-thin margin.
On medium power, this bullet averaged 711 f.p.s. and ranged from 704 to 714 f.p.s. At the average velocity, it’s pumping out 177.4 foot-pounds of ebergy.
Benjamin Pursuit 127-grain flat-nosed bullet
The Benjamin Pursuit 127-grain flat nose bullet was the speed champ in the Rogue. On high power, it launched that accurate little bullet at an average 796 f.p.s., with a spread from 786 to 809 f.p.s. At the average velocity, this little pill produces 178.73 foot-pounds at the muzzle.
It’s the medium power setting that I’m interested in for this bullet, however, because I believe I would have a bullet mold made to cast this bullet if I owned a Rogue. At this setting, the bullet averaged 747 f.p.s., with a spread from 740 to 751 f.p.s. That’s 157.4 foot-pounds of muzzle energy, on average. That’s more muzzle energy than you get from a 40-grain high-speed .22 long rifle cartridge; and, of course, the larger .357-caliber bullet does far more damage. At that power level, the Rogue would be a good fox and coyote gun out to about 100 yards.
148-grain wadcutter
Finally, I did test the 148-grain wadcutters that Dennis Quackenbush sent me. I had only a total of 10 on hand, so I tested just one shot at each setting. On high power, the bullet went 757 f.p.s., which translates to 188.37 foot-pounds. On medium power, it went 732 f.p.s., which is 176.13 foot-pounds. It might interest you to know that the Rogue is propelling this bullet at very close to the same velocity that a .38 Special midrange wadcutter cartridge produces. If you turn the bullet around when you load it — so the hollow base faces forward — you’ve created a monster hollowpoint bullet. At close range, such a bullet has few equals for destructive capability.
General observations on the new Benjamin Rogue
In case you aren’t aware, I played a small part in the Rogue’s developement, so some will think I’m biased in favor of the gun. I assure you I’m not. But this test surprised me in a number of ways. The first was the velocity stablity the Crosman engineers have been able to build into the gun. No other big bore airgun comes anywhere close to what the Rogue can do, as far as maintaining velocity with a specific bullet.
The magazine feeding problem is now gone. As long as the bullet is sized to enter the bore, it will feed fluidly through the redesigned magazine.
Accuracy has been improved. The 145-grain Nosler Ballistic Tip is still the best bullet overall, but the 127-grain Benjamin Pursuit is more accurate and more fun to shoot. If you own a Rogue, you might think about having a bullet mold made up to cast this bullet in soft lead. I hear that Mr. Hollowpoint also has some bullets that do well in the Rogue. After testing some in my .308 Quackenbush, I believe it.
The trigger is greatly improved. That was the part that Lloyd Sykes and I were worried about with the original Rogue. Well, Crosman has done it right, and I know hunters will like this one.
As far as worrying about whether a new Rogue you buy is a real new one or just one that’s left over I will say this. Crosman went to extreme lengths to remove all unsold Rogues from their dealers long before they released this new model. I’m sure those guns were reworked to the new standard. So, unless you’re buying from a hobby dealer (someone who isn’t really doing it as a business) or out the back of a car trunk, I would say you’re going to get the newer design.
I would like to thank the Crosman Corporation for providing the new Rogue for this extensive test.
Colt 1911 Special Combat CO2 BB pistol: Part 3
by B.B. Pelletier
Colt’s 1911 Special Combat BB pistol is a knockout for looks!
Happy Independence Day!
Happy Fourth of July to my U.S. readers! And to everyone else, happy Wednesday!
Today, I’ll look at the accuracy of the Colt 1911 Special Combat BB pistol. We discovered in the velocity test that the pistol doesn’t quite reach the velocity advertised. That made it possible for me to start using and testing the new Winchester Airgun Target Cube that serves as a BB/pellet trap. We also learned that the pistol shoots at dramatically different velocities in single- and double-action. Naturally, I looked at both modes in this test.
The test
I shot the pistol at 16 feet (as close as possible to 5 meters — the international BB-gun distance) from a rest. A fresh CO2 cartridge was installed at the start of the test and was used for the entire test.
The first 10 shots were to ascertain how the sights were set. Also, I knew from the velocity test that this pistol needs a couple shots to “wake up” the valve and get up to its top velocity. So, the first 10 shots were just sighters.
I discovered the rear sight needed some elevation. Happily, the sight is completely adjustable, but the direction for a vertical increase isn’t clear. The straight arrow doesn’t tell you which way to turn the screw. Fortunately, the sight works like most other rear sights, and a counterclockwise turn provides elevation. There seemed to be no click detents in the adjustment, so I watched the orientation of the screw slot.
First up were Daisy zinc-plated BBs, and 10 were loaded into the stick magazine. Then, I fired the pistol single-action, using a 6 o’clock hold with the sights. Yes, at just 16 feet from the target, I could hardly miss, but this was a test of the pistol — not of my shooting ability.
Ten Daisy BBs went into a group that measures 1.58 inches between centers. It proved to be the best group of the entire test.
Ten Daisy BBs made this 1.58-inch group at 16 feet.
Next, I loaded 10 more Daisy BBs and shot them double-action at a fresh target. As expected the group opened up. This time ten went into a group measuring 2.606-inches between centers. Although, the double-action trigger-pull is relatively light, it stacks at the end and is difficult to control. Nevertheless, this accuracy is minute-of-pop-can at the same 16 feet.
Ten Daisy BBs fired double-action made this 2.606-inch group. A stacking trigger-pull was the culprit.
RWS BBs
Next, it was time to try the RWS BBs. Though they appear to be even smoother than Daisy BBs, I find the two brands about equal in most guns I have tested. The first ten were fired single action, making a group that measures 2.369-inches between centers. That is nearly as large as the Daisy BBs fired double-action!
Once during the 10 shots, there was a double-feed, and two BBs went down range together. This never happened again, so I don’t think it’s a problem. And, if the wide shot from that double-feed was eliminated, the remaining 9 BBs made a group measuring 1.668 inches between centers — much more in line with what the Daisy BBs did.
The RWS BB single-action group looks large because the hole at the upper right is one of two that went down range together. Take it out, and the group is much closer to the single-action Daisy BB group. Overall group measures 2.369 inches, but 9 shots went into 1.668 inches.
On double-action, I was able to see several of the BBs as they went downrange. They seemed to all be curving to the left — almost as though the gun had a Hop-Up that wasn’t quite adjusted. This reminded me of the gun’s airsoft heritage. Ten shots landed in a 2.128-inch group, besting the single-action group, but only because of the double-feed while shooting single-action. This group also bested the Daisy double-action group
Ten RWS BBs went into 2.128 inches shooting double-action.
Winchester Airgun Target Cube
I used the Winchester Airgun Target Cube for this accuracy test. It’s a new combination BB/pellet trap that I’ve been eager to include in my testing. The trap is a cube of dense foam that has a metal plate inside. Shoot at it on one side, and you’re just shooting at foam, unless you chance to hit the edge of the metal plate. That’s the side for velocities below 350 f.p.s. Orient the cube the other way and the plate’s in the middle. That’s the side for velocities above 350 f.p.s.
The paper targets were all taped to the front surface of the cube. The solid backing of the cube helped define the BB holes a little. And as light as the cube is, it never moved when hit. The sound when hit is quiet, but it’s noisier than a Quiet Pellet Trap.
Daisy markets this cube and says the side of the cube that’s rated above 350 f.p.s. is good up to 1,200 f.p.s. for .177-caliber pellets. I won’t be testing it at that speed. Several shots in the same place might blow through the metal plate inside the cube, and I’m not a testing laboratory for Daisy or anyone else. I’m interested in how many practical shots we can expect from this trap, so I plan to keep a record. Hopefully the number will be in the thousands, like other commercial BB traps.
The Winchester Airgun Target Cube has its first 50 shots. Ten were from the sight-in.
The BBs all stayed inside the cube, but it’s too early to say how long this trap will last. As I use it, the tendancy will be to strike near the center of the cube, so in time we will see what effect that has.
What I like about this pistol
I like the trigger in both the single- and double-action modes. I like the adjustable sights, and I like the way the sights look when shooting the gun. I like the snazzy appearance of the gun and the way it is exactly the same size as a 1911 firearm. I like the drop-free magazine/CO2 holder. And I like the velocity that gives a lot of shots per CO2 cartridge. This gun is very quiet and only rates a two on the sound scale!
What I don’t like about this pistol
The accuracy could be better.
The bottom line
This BB pistol has to compete with many other 1911-style BB pistols that all offer a lot for the money. This one probably leads them all in looks, but it trails the field in accuracy. In the end, though, it’s more than accurate enough for a BB pistol.
Colt 1911 Special Combat CO2 BB pistol: Part 2
by B.B. Pelletier
Colt’s 1911 Special Combat BB pistol is a knockout for looks!
Wow! Today’s test is as different as any I’ve done! This air pistol surprised me completely, with results I’ve never before seen from any airgun.
The Colt 1911 Special Combat pistol shoots BBs, so a velocity test is going to be pretty humdrum. There are a limited number of different BBs to try, and they aren’t going to give fantastically different results like lead pellets do. So, usually a velocity test with a BB gun is a no-brainer for me. Shoot and record the numbers — plain and simple. But not today.
Both single-action and double-action
This pistol fires in both the single-action and double-action modes. For you newcomers, single-action is where the trigger performs the single functon of releasing the hammer to fire the gun. You have to manually cock the hammer before each shot — the trigger doesn’t do it.
Double-action, in contrast, is where the trigger both cocks the hammer and releases it, all in one smooth pull. So you just keep on pulling the trigger. As long as there’s ammunition, the gun keeps on firing.
Because the trigger is doing more for double-action, it’s always harder to pull in that mode than it is for single-action. So a semiautomatic pistol that has single-action operation will normally have the very best trigger possible. If a gun functions in either single- or double-action like most revolvers, the single-action mode will give the best trigger-pull. The double-action mode is reserved for when you want to fire a lot of rounds very fast.
There’s more to it than that, of course. Some semiautomatic pistols such as the Beretta M92/M9 fire either single- or double-action; but when they fire, the slide comes back and cocks the gun for the next shot. These guns are quick to fire the first shot, since you can carry them with a round chambered and just pull the trigger to get them started. They also have the advantage of switching over to single-action once they begin firing.
At any rate, when I have a CO2 pistol that’s both single- and double-action, I test it for velocity both ways. That often gives results that favor the velocity on one or the other of the two modes. But this gun was vastly different. It varies by about 100 feet per second greater velocity in the single-action mode. And there’s even more to report, so read my results carefully.
Single-action
I started out shooting the pistol with Daisy zinc-plated BBs in the single-action mode. The gun is rated to shoot at 400 f.p.s., so I expected something in that neighborhood; with BBs, there isn’t much variation between brands. So, I was surprised to see the first shot on a fresh CO2 cartridge register only 205 f.p.s. But sometimes pneumatics and CO2 guns need to “wake up” when they first start shooting after a rest, so I kept on shooting and watching the chronograph. The next shot went 203 f.p.s., but the one after that went 334, then 345, then 366 f.p.s. That last shot was as high as the pistol wanted to go.
My first good string of shots on single-action averaged 363 f.p.s., with a low of 360 and a high of 375 f.p.s. That’s good consistency, after the valve had woken up. I figured shooting the gun on double-action would give similar numbers. Guess again!
On double-action with the same Daisy zinc-plated BBs, the velocity averaged 252 f.p.s. The low was 224 and the high was 280 f.p.s. What a spread, and what a difference from single-action. Next, I shot two more shots single-action to see what had happened, if anything. They went 337 and 321 f.p.s., respectively. The gun was shooting slower, but it was still much faster in the single-action mode.
I then tried the RWS Match BBs that Pyramyd Air doesn’t carry. I’ve found them as accurate and precise as Daisy BBs, and sometimes they give slightly different results. This time in single-action, they averaged 319 f.p.s. with a spread from 280 to 344 f.p.s. In double-action, they averaged 240 f.p.s. with a spread from 227 to 250 f.p.s. And shooting single-action immediately following the double-action string gave me two shots at 324 and 302 f.p.s., respectively.
I was concerned that the pistol seemed to be running out of CO2, so I fired it 20 more shots double-action with no BBs in the magazine, then I fired another shot single-action (with the RWS BBs) that went 321 f.p.s. So, it wasn’t out of gas just yet!
How many shots per cartridge?
At this point in the test there were 63 shots on the cartridge. I fired another 10 blank (no BB) shots double-action and then fired an RWS BB single-action that registered 335 f.p.s. At 84 shots, the gun is still going strong.
I next shot a single Daisy BB on single-action to see if there was still such a difference between the two brands. This one went 327 f.p.s., so both BBs are going about the same speed. The initial string of Daisys was just a little faster for some reason.
I shot another 10 blank shots double-action and then an RWS BB at 327 f.p.s. So, at 96 shots, the CO2 cartridge is still going strong. Then another 10 blank shots, followed by a Daisy BB at 323 f.p.s. That was shot number 107 on the cartridge.
Another 10 blanks shots were fired double-action and then an RWS BB went 331 f.p.s. That was shot 118. Then another 10 blanks, followed by a Daisy BB that failed to register. Then a second Daisy BB went 325 f.p.s. for shot 130. Then another 10 blank shots were followed by shot 141 — an RWS BB at 321 f.p.s.
My gosh — this pistol is starting to remind me of the AirForce Talon SS using the Micro-Meter tank! Another 6 blanks were fired and then the remaining gas spontaneously released from the cartridge. All gas was exhausted, and it was all over. This cartridge had maintained its velocity down to almost the end of the CO2 charge — something I’ve not seen in a long time. For the record, I got a good 140 shots from a single cartridge.
What about the large velocity variation at the beginning of the test? I think we can chalk that up to the gun breaking in. After several hundred shots have been fired, I think the gun will perform more consistently; but I’ll come back in a special test, after we look at accuracy, and rerun the velocity test again.
Trigger-pull
The double-action trigger-pull broke at an average 10 lbs., 6 oz. of effort. The range went from 9 lbs., 6 oz. to 11 lbs., 5 oz. The faster the trigger was pulled, the lighter it became. The pull effort increases rapidly (stacks) the further back the trigger is pulled.
The single-action pull was a very consistent 3 lbs., 7 oz. The second stage is very apparent (I mean there’s a definite hesitation of the trigger blade at the start of stage two), and there’s just a hint of creep in the second stage.
So far, this ranks as a very interesting BB pistol. The test pistol fell short of the advertised velocity, but delivered a huge number of good shots from a cartridge. I think the way it turned out was better than if the velocity had been higher and the shot count less, because high-velocity in a BB gun is about the worst thing you can have. Given the tendency for BBs to rebound with great speed, you really don’t want them going too fast.
Accuracy testing is next.
Oops! My Benjamin 397 has valve lock!
by B.B. Pelletier
The Benjamin 397 (left) is a powerful multi-pump. Obsolete 397 carbine at right.
Today, we have a critical report about airgun maintenance and operation. So, if we’re being critical, let’s start with the title. It’s a It’s no one’s fault — let’s all get along title. It should read, Oops! I really screwed up! And when I say “I,” that’s exactly what I mean!
About a month ago, a friend of mine — who shall remain nameless, unless he repeates what I am about to tell you — received a new Benjamin 397 multi-pump pneumatic. Hurray!
I went over all the operational and maintenance steps carefully with him — pump it no more than 10 times per shot, always store it with one pump in it, use Pellgunoil on the pump head etc. — and then turned him loose with his new rifle. Last week the rifle came back to me with the complaint that it didn’t fire pellets anymore.
I must have looked like that old plumber who knows just where to tap the pipe to get the system going again, because before I even examined the rifle I told him it was over-pumped and therefore valve-locked. Then, I took the rifle and opened the pump handle, which sprang open with a lot of force. Yep — it’s valve-locked, all right!
I listened carefully to the story of how it couldn’t possibly have been anything that he did wrong. I’ve heard that same story a hundred times before; but like a compassionate priest, you have to let them confess everything as you listen in silence. On about the third go-round, I got the real story.
It seems he was at work, shooting his new gun with a buddy who was also shooting his own multi-pump. Remember, folks, we’re talking Texas, here. Depending on your job, shooting at work isn’t that uncommon. Perhaps not at a funeral home or at a fast-food franchise, but there are a lot of outdoor jobs where shooting is possible and not objectionable.
They were shooting at a metal sign that the buddy’s gun wasn’t able to dent very much, but the 397 put a big ole’ dent in it. However, something wasn’t right! It seems the other guy’s pump gun was much easier to pump than the 397. What was wrong with the 397?
What was wrong with it was that it wasn’t a Crosman 760, like the other guy’s gun! At least that’s my guess. I’m still waiting to hear what the other guy’s gun was.
So, his new gun was harder to pump, but it was also a lot more powerful. MAYBE he wanted to see if the 397 would go all the way through the sign, thus vexing his friend, which is the tradition whenever two guys shoot together. He pumped it ALL the way up, being VERY CAREFUL not to exceed the 10-pump limit, as I’d instructed him. But that time it fired only weakly.
He handed his rifle to his friend, who then pumped it up again, also being VERY CAREFUL not to exceed the 10-pump limit, because the owner was watching him. This time when the trigger was pulled, the gun just went CLICK and no pellet came out. So, now he knows that his gun doesn’t work anymore.
At least he stopped when it got to this point. He didn’t keep loading pellets and pumping it a couple more times just to be sure. I have seen owners do that before.
He brought me the rifle and asked if I could possibly help him. I told him there are two ways to go about this. One is to wait a couple months and hope that the gun leaks down enough that the valve is no longer locked. If the gun had not been properly oiled with Crosman Pellgunoil, that might have been a possible solution. But it was well-oiled, and I didn’t think it would leak down in even a year!
I decided to go the other way. I would remove the extra air mechanically by partially disassembling the gun and rapping on the valve stem with a heavier hammer. That’s how the repair center fixes guns that are over-pumped. Or, at least it used to be! This is where the “old plumber” became a student, again.
I discovered that the new 397’s design is vastly different from what I was used to. You can no longer do what I just said because the gun is not designed to allow it. The new design is much cheaper to build and easier to repair — except when the gun is over-pumped. I’ll describe what I did and what happened as a result — and I don’t see any other way of doing the job.
Poor photos today
I apologize for the poor photos that follow. I was working on the gun and getting dirty, so I used the flash on the camera to make the work go faster. That’s why everything is so over-exposed.
What appears to be the stock screw also holds the valve inside the pressure tube. If the rifle is pressurized, this screw will be under pressure from the valve body trying to move! If this is the case, remove the bolt before you loosen this screw!
The new 397 valve is held in the gun by the single stock screw. That screw fastens the trigger group to the action, and there’s no way to rap out the air the way I described it earlier. I did an internet search and discovered there were no instructions on what to do! In fact, everyone dances around this design almost as though they don’t understand it, though I’m quite sure most of them do. It’s so much simpler than the guns I’m used to. When a gun is over-pumped, there seems to be no good way of depressurizing it — other than to remove the single screw I just described and let the air blow out. But before you do, be sure to remove the bolt first!
Remove the two sideplate screws and the sideplate and cocking plate will come off (right and left, respectively in this photo). Then, you can remove the Allen screw from the bolt.
Once the Allen screw is out, the bolt slides out of the receiver.
I didn’t know it while I was doing it, of course, but when the stock screw backed out sufficiently far, the air exploded out of the gun as the valve moved within the pressure tube. It caught me by surprise, but in retrospect I can’t see a better way of doing the job. If anyone knows of one, I’d like to hear what it is.
In retrospect, I should have removed the bolt from the gun before removing the stock bolt. To do that, remove the two screws that hold the sideplate to the left side of the action, exposing the Allen screw on the bolt that cocks the hammer. Then remove the Allen screw, and the bolt slides out of the action.
The action can be removed from the stock when the one Phillips screw is loose. The screw is captive inside the stock and doesn’t show here.
At this point, I finished the disassembly, checked all the parts to see that they were okay, which they were, and assembled the gun again. There’s a trick to assembling this gun. The pump arm must be swung forward to allow the valve to go forward enough for access to the screw hole. If you do that, this is an easy pneumatic to assemble. If you don’t — good luck!
You’re looking through the screw slot in the triggerguard at the brass valve body and its fastening screw hole. How many people would realize that their one stock screw is holding all this?
This picture shows why you cannot just rap out the air anymore. The rear of the pressure tube is blocked by the back of the trigger assembly, which has to be removed to gain access to the valve.
And how does it work?
The rifle now works fine, but I’ll run a little test to see how fine. I’ll shoot the gun through a chronograph on six pumps, and keep increasing the number of pumps until there air remains in the gun after the shot. Then, I can tell the owner what the exact maximum safe number of pumps are for this specific gun. That’s another great reason for owning a chronograph!
Checking the velocity
I decided to use Crosman Premiers in the 7.9-grain weight for my test pellets. This is what the gun now does.
Pumps…Velocity…Air remaining?
6………….613………..No
7………….650………..No
8………….688………..Yes! A soft pop was heard.
9………….713………..Yes — a second shot went 555 f.p.s.
Chronograph reveals what happened
It’s easy to see what happened to this rifle. I told the guy that 10 pumps was the maximum, because I thought that was what the owner’s manual said. But it isn’t! Crosman has folded the Benjamin rifles and Sheridan rifles together, and now they all top out at 8 pumps. So, I was responsible for the owner over-pumping his gun! Several years ago, when the Benjamin and Sheridan brands were different, the Sheridan stopped at 8 pumps but the Benjamins stopped at 10. But those days are over. Now they all stop at 8. So — shame on me! Apparently this is my week for confessing my sins.
What if you don’t own a chronograph?
But you don’t care about that! You care about your own air rifle, and, since you don’t own a chronograph yet, how can you determine the exact number of pumps that are maximum for your rifle? It’s simple. Do what I did above and increase each shot by one pump. Then cock the rifle afterward and fire it again without a pellet. Listen for the pop of escaping air. When you hear it, back off one pump and that is the maximum number of pumps your rifle can handle.
Just to be safe, pump your rifle to the newly established maximum number of shots five times and shoot it. After the fifth shot, cock the gun once more without pumping it and fire it again, listening for a pop. Sometimes the amount of air that remains is so low you cannot hear it, but after a cumulative five shots, you should be able to hear it very well.
Lessons learned
I got the tables turned on me this time. And I also learned how easy it is to work on these new Benjamin rifles. And you readers got to watch everything over my shoulder, plus you got a new way of testing the maximum number of pumps for your specific pump rifles if you don’t own a chronograph. I would call that a good day’s work!
Quackenbush .308: Part 4
by B.B. Pelletier
Quackenbush .308 big bore is an attractive airgun.
The last time we looked at this Quackenbush .308 big bore was when I discovered that my rifle really likes Mr. Hollowpoint’s 68-grain hollowpoint bullet. I also tested a 150-grain Loverin-design bullet that was just a bit too heavy for the gun. It didn’t want to stabilize and was tearing elongated holes in the target at 50 yards.
If you’ll recall, I was running low on air that day, so I could fill the rifle to only 3,000 psi. That gave a stunning group that was smaller than one inch at 50 yards with the 68-grain hollowpoint, but I wondered whether it would do any better if I filled the rifle to higher pressure. I also wondered if going just a trifle faster would have stabilized the 150-grain bullet. There were a lot of unanswered questions after the last test.
Today, I’ll address those questions. I had a full air tank and a reasonably good day at the range. Certainly for testing something as stable as a .308, the light breeze was no challenge.
Shooting the 68-grain hollowpoints
I decided to fill the rifle to 3,500 psi, to see what kind of velocity that might give. The 68-grain bullet averaged 1051 f.p.s, on that much air and left about 3,100 psi in the tank for the second shot. That’s a muzzle energy of 167.15 foot-pounds.
Shot two averaged 1,010 f.p.s. with the same 68-grain bullet and generated 154.07 foot-pounds of energy. You might think that’s close enough to the first velocity that the bullets will print in the same place. They might if this was a firearm — but it’s an air rifle, and we have to take the flexing of the horizontal air reservoir into account. As the pressure inside the air reservoir changes, the reservoir — which is a long tube — flexes a tiny bit. Since it’s connected to the barrel, this flexing can cause movement in the muzzle.
The first shots printed about two inches higher on the target than the second shots. I knew they would from past experience shooting other big bores, so this came as no surprise to me. I actually shot one group of first shots (after a 3,500 psi fill) at one target and a separate group of second shots at a second target.
After seeing where the shots landed relative to the aim point, it’s possible to use the mil-dot reticle in my scope to shoot both shots into the same group by using two different aim points. This is a technique I learned several years ago with my .458 Outlaw; and with it, I can put five bullets into one inch at 50 yards. I didn’t try that on this day, however, because I was too busy learning the gun.
Neither group obtained this day was as good as the group I shot last time on just 3,000 psi of air. The first group that was shot on 3,500 psi measured 2.72 inches between centers for five shots, though four of those shots landed in a group measuring 1.219 inches.
Four of the five bullets were close at 50 yards on 3,500 psi. Two landed in the same hole.
The group that was fired on 3,100 psi measured 1.953 inches between centers. That’s twice the size of the best group that was shot several weeks ago on 3,000 psi, so I think this bullet is going too fast for best results. It looks to me like this 68-grain hollowpoint wants no more than 3,000 psi as a max charge. That would put the velocity at around 970-980 f.p.s.
Lower starting pressure gave a tighter group. This one was made with 3,100 psi.
Did the 150-grain bullets stabilize?
Again, the 150-grain bullets failed to completely stabilize — even when driven to 825 f.p.s (on 3,600 psi air) and generating 226.75 foot-pounds of energy at the muzzle.
Both bullet holes show evidence of tipping. The bullet is not stabilized.
Clearly, this Loverin bullet is too long to stabilize at the velocity this rifle generates. What’s needed is a 120- to 130-grain bullet that’s short, which means it must have either a round or a flat nose.
Some observations
I’m seeing a relationship between soft pure lead bullets and better accuracy. Any hardening alloy seems to open up the group.
Ditto for lubricated bullets. So far, the best, most accurate bullets are those that are completely dry. I see now that I need to cast some more 130-grain bullets in lead that is as pure as I can make it, and shoot them absolutely dry. I’ve seen the performance of pure lead bullets on game, and they hold together far better than hard alloy bullets do. Lead hardened with antimony breaks apart in large chunks, while soft lead mashes up like a wad of bubble gum when it hits game.
I’ve always questioned using a .308 for game as large as a deer. I know hunters who are better shots than I am do it all the time and have great success, but for me the .308 is more of a coyote and bobcat round. I’ll leave the deer and wild hogs to the .458 and keep this .308 for smaller game. It probably has a useful range of 125 yards in my hands. For an air rifle, that’s pretty far!
Quackenbush .308: Part 3
by B.B. Pelletier
Announcement: Tyrone Nerdin’ Daye is this week’s winner of Pyramyd Air’s Big Shot of the Week on their facebook page. He’ll receive a $50 Pyramyd Air gift card. Congratulations!
Tyrone Nerdin’ Day says this about his winning photo: Me and my IZH-DROZD MP-661k Blackbird with Wild Mod Chip, Walther PS 22 red dot sight, quad rails and a UTG Tactical Op bipod. Black SWAT vest with the Walther CP99 Compact, police belt with Winchester Model 11.
Quackenbush .308 big bore is an attractive air rifle.
It’s been a long time since Part 2 because I was searching for a better bullet for this rifle. Oh, the groups shown in Part 2 aren’t that bad; but when you see what I have to show today, you’ll be glad I stuck with it.
Most of my experience has been with Quackenbush’s larger calibers. My Quackenbush .458 Long Action rifle is so accurate that I was pretty sure I could get better performance out of this .308.
The .308 is the big bore gun everyone talks about these days. Guys are taking deer and goats with them out to incredible distances. At the 2012 LASSO big bore shoot, they were hitting half-sized sheep silhouettes out to 300 yards and making it look easy. But the bullets I had didn’t seem to want to perform like what I saw from other guns. So, I kept searching and trying different bullets.
Blog reader Robert from Arcade even sent me a batch of 150-grain Loverin-style lead bullets he cast himself. They were big and heavy, and my rifle wasn’t doing that well with lighter lead bullets, so I didn’t have a lot of hope for these. But I took them along to the range yesterday, where I tried them along with a remarkable new bullet that I picked up at the Arkansas airgun show this year.
Mr. Hollowpoint saves the day!
At that show, I asked Robert Vogel, who’s Mr. Hollowpoint, for a good bullet for my rifle. He recommended a new hollowpoint he’s casting that has had some good reports. At 68 grains, it’s a featherweight compared to the 115 to 130-grain bullets I’ve been shooting, and I thought maybe the additional velocity I’d get might make the difference. So, I bought a bag to try.
I got out to the range on Wednesday, and the day was very close to perfect. At 88 deg. F, it was a bit warm, but the wind was very low and never did pick up.
The 150-grain Loverin bullet on the left and the 68-grain hollowpoint at the center and right were both tried. Notice the uneven base on the hollowpoint. It seemed to make no difference on the target. That large hollow point lives up to its name!
My carbon fiber tank would soon need a refill, so I was only able to fill the rifle to 3,000 psi, and I held the number of shots per group to 5 instead of 10. The first shot was low and about three inches to the right of the bull, so I cranked up the elevation and put in some left clicks and then shot a 10. It was nothing but luck that the one adjustment put the bullet in the right spot.
It doesn’t get much better than that, so I refilled the rifle and shot again. I was filling after each shot, so every shot had the benefit of a 3,000 psi fill behind it. With the Quackenbush Long Action Outlaw, and to a large extent with all other big bore air rifles I’ve tested, the first and second shots group in different areas — but they do group tight. The trick is to use some extra elevation for the second shot so it goes to the same place as the first. But since I didn’t know exactly how much elevation to use with this new bullet, I refilled after each shot instead.
It was a slow, methodical process of settling into the rest, sighting, squeezing off the shot, then returning to the tailgate of my truck to top off the reservoir for the next shot. My shooting buddy, who witnessed all this, was impressed by how much recoil this .308 has. Of course, it recoils with or without the bullet, because the air that’s exhausting is giving the rifle a rocket push.
By the time the fifth shot had been fired, I could see the results through the scope. The group was tight and well-centered, and the last three shots were in the x-ring, which is in the center of the 10. They can be covered by a dime. So, this 68-grain hollowpoint from Mr. Hollowpoint is the bullet my .308 likes!
Five shots went into this 0.975-inch group at 50 yards. The 68-grain bullets from Mr. Hollowpoint are a real winner in my Quackenbush .308. The center three bullet holes can just be covered by the dime.
The base of the bullet has an uneven ridge extending past the base. It’s the result of sizing the bullet, because Robert Vogel sizes each and every one to .308. Normally, I would worry about anything on the base that isn’t perfectly uniform; but after looking at the target, I can see that this has little affect on how this particular bullet flies.
This bullet loads very easily in my rifle. There seems to be no resistance when the bolt is closed. They’re cast from pure lead, which leaves them soft and prone to deformation. Performance on game is enhanced through the combination of the soft lead and the hollowpoint design. A soft lead bullet holds together better than one that’s hardened with antimony, so these bullets still penetrate deeply in game. Elmer Keith wrote extensively about the performance of soft lead bullets on game with handguns, and the velocity of these big bore rifles is pretty close to what he obtained.
I wouldn’t use such a light hollowpoint on a whitetail deer-sized animal, but it ought to turn a coyote or a bobcat inside-out! And the rifle is now zeroed at 50 yards — huzzah!
From light to heavy
Next up was the Loverin-style 150-grainer from Robert of Arcade. Since the rifle was only so-so with the lighter bullets I’d tried, I didn’t think it would stabilize this long lead slug, but it wasn’t much trouble to try. Robert also casts these from lead as pure as he can get; so, like Mr. Hollowpoint bullets, they’re just right for airguns.
A Loverin bullet has many grease grooves along a relatively long body. It was greatly in favor in the early 20th century. When jacketed bullets came along, they sent the best lead bullet designs into relative obscurity. Only those who cast their own bullets are aware of the differences in designs like the Loverin, and this style bullet is no longer popular with mold-makers today. If I want to get a Loverin mold, I either have to buy a custom mold or I have to watch the auction sites for a vintage mold to come up for sale. This one is Lyman mold 311466.
In contrast to the easy loading of the 68-grain hollowpoint, these bullets were hard to load. They were not sized and measure up to 0.311 inches in diameter. I normally shoot unsized lead bullets in my big bores whenever I can to ensure the best sealing of the bore — a little resistance at loading is normal.
The bullets landed lower on the target, as expected, and they were about a half-inch to the right; but after 5 shots, I was impressed by the group they made.
By this point, the carbon fiber tank was definitely running out of air. On the final two shots, it filled the rifle to only 2,950 psi. Since the resulting group seems elongated up and down, I will attribute some of that to the uneven fill. I think that if I shot this bullet at a higher-pressure fill, the performance might improve.
Notice, also, that the bullet holes seem elongated. There was some tipping going on, and this bullet is probably at the ragged edge of stability at this velocity — whatever that is. A higher-pressure fill will probably boost velocity enough to correct this at 50 yards.
Five shots went into this 2.008-inch group at 50 yards. The Loverin-design bullet did remarkably well, considering its 150-grain weight. The last two fills were only 2,950 psi. I wonder what a higher, more uniform fill might do?
This longer, heavier bullet would be ideal for deer. While the velocity is probably down at the 700 f.p.s. mark, these bullets still shoot all the way through deer unless they’re stopped by heavy bone. I would restrict my shots to very close range with this bullet, but I think it might do the trick out to 80 yards, or so.
What’s next?
Now that I have one good bullet for sure and the possibility of another, it’s time to test both with higher fill levels. I also want to chronograph these bullets so we can see what sort of performance they give.
I also want to cast some of my 130-grain spitzers in pure lead and shoot them unsized and unlubricated. That might be the secret to success in this rifle.
We’re not quite done with the Quackenbush .308. My thanks to both Mr. Hollowpoint and to Robert from Arcade for providing me with these two bullets to test.
