Posts Tagged ‘multi-stroke pneumatic’
Benjamin 347 multi-pump pneumatic: Part 1
by B.B. Pelletier
Benjamin’s 347 multi-pump was sold between 1969 and 1992.
The Benjamin 347 is a single-shot, multi-pump pneumatic made by the Benjamin Air Rifle Company of St. Louis from 1969 through 1992. Most of what I will say about the 347 (the .177-caliber version of the gun) also applies to the .22-caliber model 342.
There are two variations of this gun. The model I’m testing for you today is the first variation. It is characterized by a checkered pistol grip and forearm and was made from 1969 until 1986. The second variation has a plain stock and went from ‘86 to ‘92.
This closeup shows the checkering on the 347 pistol grip. Not great, but what do you expect?
This is the model that took Benjamin out of the old days and into the modern era, where the successor models 397 and 392 took over and remain current today. The rifle just prior to this one was the model 317. It was also an underlever pump like the 347, but Benjamin had used the same model designation for an earlier front-pump, pushrod-type multi-pump that was made before World War II.
When I got back into airgunning seriously in the early 1990s, the presence of these two different Benjamin airguns with the same model number caused a lot of confusion; but now that Crosman has brought out the now-discontinued Benjamin Super Streak, a breakbarrel spring-piston rifle, most collectors have gotten used to the idea of model name reutilization.
The rifle
The 347 is generally the same as all underlever multi-pumps that went before and came after its time, but don’t think there are no differences. For years, I’ve told people that a 347 is just an older 397; but now that I have both of them to examine, I can see several differences. The first is the overall length of the gun. The 347 is just under 34-1/2 inches long, while the 397 that I have is 36-3/4 inches overall. All that difference appears in the stock, as the barreled actions are exactly the same length. That’s important, because the length of the barrel determines the maximum velocity the rifle can achieve.
While this is not a report on the 397, I’ll say that the first 397 rifles looked remarkably similar to the 347. Over time, though, certain features — such as where the safety is placed and how the rear sight works — have changed. Today, the 397 is quite a different rifle, though at its heart it’s still a multi-pump with the same capability as all other similar guns.
The pull on the 347 is just 13 inches, which is about 7/8 of an inch less than the 397 and about 3/4 of an inch more than the 397 carbine. I compared it to the specs Mac gave us for the 397C, and it turns out to be just a little longer over all and heavier (at 4 lbs., 12 ozs. compared to 4 lbs., 4 ozs. for the carbine). So, this is a smaller air rifle, yet still sized for an adult.
The safety is located at the rear of the receiver and is a push-pull type similar to many shotgun safeties. It’s entirely manual.
The bolt is just bent from a solid rod. The safety. located behind the receiver tube, is manual and slides in and out. It is convenient to the thumb.
The trigger is another interesting feature. While it’s quite simple in design and operation, it has an average 46-oz. pull-weight and is reasonably consistent (within 3 oz.). That’s under three pounds and quite a bit better than the lawyerly 5-7 lb. triggers we see on multi-pumps today. The blade is very wide and flat and feels good to me.
Sights
The rear sight is adjustable in both directions, though both adjustments are crude. To adjust windage, loosen the rear screw on the sight leaf and push the whole sight in the direction you want the pellet to go. For elevation, there’s a stepped elevator that sits under the rear leaf. I’ll find out how well they work when I test the rifle for accuracy.
The rear sight has crude adjustments for both windage and elevation.
The rear sight notch is very wide in comparison to the front blade. A little extra light on either side of the front blade is good, because it allows you to frame the front blade exactly in the center. But this seems to be too much; and once, again, I’ll find out when I shoot it for accuracy.
The 347 will accept the Williams peep sight, but the receiver isn’t pre-tapped for it. That was a marketing mistake on Benjamin’s part, and Crosman corrected the situation when they took over the company. Owners do not want to drill and tap holes in their receivers, and why should they? Even though the receivers on all Benjamin pneumatics are made of brass that’s easy to drill, it’s an extra step that most people just will not take; but if the holes are already there, quite a number will decide to try the peep sight.
As far as scoping the rifle goes — my advice is to forget it. The intermount that fits on the barrel of a rifle like this is so prone to break the barrel solder joint from flexing it with the extra weight of a scope that it isn’t worth the attempt. My advice is to just use open sights on these older multi-pumps. Of course, there have been receiver bases for the modern Benjamin rifles that change everything, but I don’t know if they’ll work on an older-profile receiver like the one found on a 347.
Maintainability
Though the parts are no longer generally available for an older model like the 347, there are plenty of service stations that are making and modifying parts for these guns. So, they can be repaired and rebuilt. The pump piston rod in the rifle is adjustable for wear. As the power drops off, the pump rod can be turned out (made a little longer) to make the piston head go closer to the inlet valve, thereby pushing more compressed air into the valve/reservoir when the rifle is pumped. It’s not a means to hot-rod the gun, but to tweak it back to original performance when it gets a little tired.
Naturally, the best maintenance for any airgun like this is to keep the pump head moist with Crosman Pellgunoil, which helps it maintain a seal against the walls of the compression tube when it moves. For long-term care, leave a pump of air in the gun when it’s stored. That seals the valve against airborne dirt that can quickly destroy the seals. A rifle thus stored can be expected to function for many decades.
My pet peeve
The rifle says “Benjamin Franklin” on the left side of the receiver tube. I knew that was a play on the company name when I was nine years old and inherited my father’s model 107 pistol. For some reason that I cannot fathom, adults in their 60s still don’t get it and think the rifle is called a Benjamin Franklin. Nothing sets me off quicker that when someone makes this mistake. Sorry, but you’ve been warned.
The presence of quotation marks around the name, Benjamin Franklin, indicates that it’s not real. It is, in fact, just a play on words. Since the company name is Benjamin, they wrote Benjamin Franklin on all their guns during certain years. There was never a Benjamin Franklin airgun model, nor is there any other connection to the name.
Another factoid
All Benjamins are made of solid brass. It’s amusing to see one all polished like a trumpet and the owner thinks he has the greatest thing in the world. In fact, they’re all solid brass under the finish. At gun shows, it tickles me to hear dealers talking with pride about their “all-brass Benjamin Franklin” when the guns are still made of the same materials today.
Putting things into perspective
A look at a 347 is a look back into history. This rifle was made when the old Sheridan Blue Streak with the classic rocker safety was made and should be equivalent to it in most ways except power. As a .177, this rifle will always come out on the short side of a power test because pneumatics like to push heavy pellets for greater power. However, velocity will be greater for the smaller-caliber guns. So there’s a balance.
This should be a fun gun to test.
Postscript
Last weekend, I heard a funny line in the new movie Contagion. One of the main characters was a blogger portrayed by Jude Law. A doctor, played by actor Elliott Gould, told him that a blog is just graffiti with punctuation.
Myths of the multi-pump
by B.B. Pelletier
When I started The Airgun Letter back in March 1994, I did so out of frustration. I had just subscribed to American Airgunner magazine and they folded, leaving me with half a subscription unfulfilled and an unquenchable thirst for more information about airguns. I could buy all the gun magazines I wanted, because there were over a dozen titles on the newsstands back then, but there was never one about airguns. And, the few articles gun writers wrote about airguns were trash back then…just as it is today.
Edith suggested that I write my own magazine about airguns, and I thought she was crazy. I told her I didn’t know enough about them to fill a whole magazine, so she suggested that I write a monthly newsletter, instead. I still thought she was out of her cabeza, but at her suggestion I sat down one day and wrote the titles of all the articles I knew I could write about. When I had three-and-a-half legal sheets filled with one-line titles (about 150 titles) I figured it might be worth a try.
The rest of the story is that we started publishing the newsletter in March 1994 and added 50 percent more pages a year later because I needed the extra space. Then, we also published six different 100-page magazines called Airgun Revue, for which I wrote historical airgun articles.
The only reason we stopped publishing the newsletter was we were losing money. People were copying the newsletter and sending it to their friends. I had thousands of readers the world over, but most of them were not paying for a subscription. Plus, the internet was growing, and we also found some of our articles online. In those days, it was harder to shut down another website for infringing on your copyright.
Balderdash!
But back to today’s report. One thing I did when I wrote my newsletter was address topics that no other writer would. There were deep dark secrets back in those days, and various interest groups didn’t want the great unwashed (that’s everyone except themselves) to know these things. So, I wrote about them in a column called “Balderdash.” Two of them have to do with today’s blog.
There were several myths about multi-pump pneumatics that were being espoused on the few chat forums we had back then. One was the myth that a multi-pump loses power when left to sit for a long time after pumping, because pumping generates heat (the heat of compression); and when the gun has the chance to cool off, it will slow down significantly.
Another myth was that the cadence at which you pump each stroke has a tremendous effect on the power output of the gun. I’m going to answer those myths right now.
I tested both questions, using my Sheridan Blue Streak and a Japanese-made Sharp Ace I owned and found that pumping the gun fast or slow had virtually no effect on velocity. There were differences, but they were smaller than the total variation of velocity both guns had, so the results were “in the noise,” as electronic engineers like to say. There was no difference in the velocities of the guns whether they were pumped slow or fast that could be supported with statistical confidence.
What about shooting immediately as opposed to waiting for a long time? Would velocity vary then? Many said that it would, because the heated reservoir (and the air inside) would have time to cool and therefore lose energy. W.H.B. Smith claimed in his classic book, Smith’s Standard Encyclopedia of Gas , Air and Spring Guns of the World, that there would be a difference from the loss of heat over time, but it would be very small. Back in 1995 when I ran this test, Smith’s book was one of the only books on the subject of air-gunnery in existence. We knew even then that there were errors in the book, such as the low results he got with the HW 54 EL Barakuda ether-injected rifle that was probably due to a blown piston seal. But since it was just about all there was, we read it and thought about it and this idea of power loss through cooling became a fact.
The test I ran with my Sharp Ace indicated a small difference in power that favored the hotter gun over the gun shot later, but the results were, once again, very close. At about 770 f.p.s., the two results were separated by just seven f.p.s. for 10 shots. I concluded that the difference might actually exist, but that it was too small to be of practical interest.
But let’s set those two questions aside now, because yesterday, blog reader Aaron prompted me to write this blog when he responded to my test of accuracy between the Ruger 10-22 and the AirForce Talon SS that wrote about in yesterday’s blog. Aaron said that he could not understand comparing airguns to powder burners. That each was created to do a different thing and that any comparison was therefore senseless (I’m using my own words to paraphrase his thoughts here).
I agree with Aaron that we shouldn’t compare airguns and firearms — except that so many people do. When I was growing up, I heard a lot of older boys and even men saying, “That old Benjamin of mine is as powerful as a .22. I just pump her up 30 times and she cracks like a rifle!”
Overlooking the fact that the gun they were talking about probably was a rifle, I understood what they meant and I’m sure you do, too. What they meant was their multi-pump, when pumped about 30 times, had (they assumed) all the velocity and (they assumed) power of a .22 rimfire cartridge.
At this point, blog reader twotalon chimed in to tell us he knew what the outcome of this test would be. Well, he was right, but there is a VERY important point that we all need to understand. While conducting the first test about the speed of the pump strokes affecting the velocity, the first time I ran the test I actually proved that it did! And I published the results that way!
Several people took exception to my findings, and at about the same time I was testing the Beeman R1 for the articles that would eventually become the R1 book. Well, I discovered that my ancient Shooting Chrony chronograph that I bought used from Paul Watts could be “tricked” into displaying velocities faster or slower, depending on the angle of the pellet path through the skyscreens. I had to throw out a lot of R1 test results after I found out how to “cheat” the machine by angling the barrel for the shot. And that made me wonder about everything else I had tested with the same machine, so Edith and I bit the bullet and I bought a new Oehler 35P chronograph.
The new chronograph showed that there was very little difference between slow and fast pumping, so I had to print a retraction to the earlier article. I also learned the value of good equipment, because I had to rerun a lot of the R1 tests that were already in the can.
I’m not saying anything bad about today’s Shooting Chrony chronographs. I use one most of the time these days. But the one I had been using for those tests was one of the very ancient ones that had cardboard “windows” above each skyscreen, and the ones on my machine had been so shot to pieces that the results were unreliable. You’d get a three-digit number, but how close it came to the truth was anyone’s guess.
Back to the report
At any rate, I’d always wondered if the old guys were kidding themselves by thinking an overpumped pneumatic was more powerful, so I conducted a test. I really didn’t want to pump my Blue Streak more than eight times because ever since it was brand new in 1978 I’d been so careful to limit my pumps to a maximum of eight, just like the manual advised.
I’m sure that I conducted that test and published the results somewhere, but I can’t find it anywhere in the index of the Airgun Letter. So, I had to run another test for you today. Once again, I drafted my 1978-vintage Blue Streak for the job. And we remember that the manual that I lost years ago, but which Pyramyd Air has in their online library of manuals, says that 8 pumps are the maximum. So, let’s roll!
For this test, I used my old Blue Streak, which I oiled especially for today. The pellets are all 14.3-grain .20-caliber Crosman Premiers.
Pumps….Velocity
3………….410
4………….431
5………….453
6………….459
7………….461
8………….467
9………….491
10………..495
11………..475
12………..471
Well, that chart shows what I was talking about, but not as well as I’d like. You can see the power drop off after the tenth pump stroke. But a Blue Streak should be doing that on pump number nine and the velocity should be much higher.
I could tell at pump five that my old Blue Streak wasn’t feeling well. It looks like the old gal finally needs some attention, because the last time I recorded the same pellet at 8 pumps it was going 643 f.p.s. and a few years before that it was close to 675. There’s reason No. 12 to own a chronograph.
Next, I pressed a Benjamin 392 into service. These days there isn’t much difference between the 392 and the Blue Streak, except for the caliber. My 392 is a pump-assist model that I reported on several years ago, but the powerplant is stock.
Same Crosman Premier 14.3-grain pellet was used, but this time in .22 caliber. Again, the gun was oiled before testing began.
Pumps….Velocity
3………….421
4………….488
5………….540
6………….572
7………….602
8………….625
9………….637
10………..654
11………..614
12………..667
13………..622
14………..632
15………..639
That wasn’t the clear and obvious test result I was hoping for. In the past, I’ve seen velocities turn around after pump eight, or in some guns after pump nine and everything thereafter was slower. This time, the gun kept increasing until pump 13, where it went slower for the first time, but after that it seemed to want to remain at about the same velocity no matter how many pumps were put into the gun. This wasn’t from residual air pressure remaining in the reservoir, because I was dry-firing the rifle after each shot from seven pump strokes on. Usually, I’ll be able to hear when the gun hasn’t exhausted all its air because there will be a small crack from the dry-fire afterward, but that didn’t seem to be happening with either my Blue Streak or this 392. The Blue Streak just needs an overhaul but there could also be some dynamic about the pump-assist conversion I’m not familiar with, I guess.
But the main point I wanted to make today was that the gun doesn’t just keep on getting faster and faster with each additional pump stroke, and that was proven in both tests. So, the myth of 30 pump strokes turning it into a .22 rimfire is just that — a myth.
I’m not blaming Aaron for any of this. He only said he didn’t think we should compare airguns to firearms. He never mentioned any of these old stories, but that was enough to set me off on this strange quest to expose some old-wives’ tales about our airguns.
Now, I have yet another sick air rifle to care for. It seems that the cobbler’s children will have to go barefoot a while longer.
Benjamin 397C: Part 3
by B.B. Pelletier
Photos and tests by Earl “Mac” McDonald
The Benjamin 397C (right) is noticeably shorter and smaller than the 397 long gun. It’s three inches shorter and more than a full pound lighter than the rifle we know today.
Before we begin today’s report, I’d like to give you an update on two projects. First, I’ve replaced the trigger in the RWS Diana 34 P rifle, so I’m ready to do the T06 trigger evaluation. It was the easiest trigger replacement/piston removal I’ve ever encountered! I used to think Weihrauchs were easy to work on, but now that Diana has gotten rid of the T01 trigger that had a couple small things you needed to know how to do, replacing a trigger in one of their rifles is about like putting batteries into an airsoft AEG. I did the whole job in 20 minutes, start to finish, which included set-up and clean-up time. A lot of the credit for that goes to the Air Venturi spring kit that was in the gun, because the mainspring is not under a lot of pre-compression. I’m sorry to see that product go, because it made a world of difference in the performance of the gun.
I was so pumped with the success of the trigger swap that I tackled the Slavia 631 next. It’s also easy to take apart, and you won’t believe the improvement that just lubrication has brought. A 35-lb. cocking effort is now down to just 21 lbs.! I had guessed it could drop to 28 lbs., but that was way too conservative. I also got rid of 80 percent of the vibration, but that’s something I will save for the next report. Since the rifle is now so different from the way it was, I’m going to retest the velocity for you in a special report.
There’s lots more to tell about both projects. This was just an update to let you know how things are going. And, wprejs, this week I’ll pack the harmonica rifle and send it to Vince. Now, let’s look at today’s test.
Let’s take a look at the accuracy potential for the Benjamin 397C that Mac’s been testing. There’s been a lot of interest in this little rifle since this report started, and practically nobody knew of the gun’s existence before now. Even so, it was produced so recently that there’s still a good chance of finding one in near-new condition and still in the box, so this is one of those sleeper opportunities that abound in this hobby. As I finish this report, you have to ask yourself what it is that you like about airgunning; because if it’s finding rare guns for very little money, this carbine is one to look for. And, you need some references like the Blue Book of Airguns to help you find things like this.
The test
Because this is a multi-pump pneumatic, there are some things we need to know before we look at the targets. The number of pumps that were used for every shot. Mac shot the carbine off a rest at 25 yards, and each shot got the maximum of eight pumps.
The way this gun works, some high-pressure air will always be trapped in front of the pump piston head after the pump stroke is finished. All the air does not go into the reservoir, even on modified guns.
As the number of strokes increases, the amount of air trapped in front of the piston head increases, so naturally it’s always the greatest when using the maximum number of strokes. When that happens, the air pushes back on the piston head, forcing down the pump lever, which is the carbine’s forearm, just a little. When you shoot, the air pressure inside the reservoir drops instantly and the tiny bit of high-pressure air in front of the pump piston head pushes its way into the reservoir. That allows the forearm to return to its relaxed position, and the shooter feels this as the whole gun settling. It’s a trait very common to a multi-pump, and it allows some movement of the gun with the shot.
There’s nothing a shooter can do about this movement when it happens; when it does, the pellet is already out of the barrel. The slight movement should have no effect on the accuracy of the gun. However, I want you to remember this discussion, because it had an effect on the outcome of the test.
Mac notes that the little carbine is hardly a bench gun, and we wouldn’t expect it to be at just 4 lbs. Sometimes, light weight and overall shortness can be a detriment to accurate shooting, as these little rifles are so twitchy (sensitive to how they are held).
You’ll remember from Part 1 that there is a Williams peep sight on this gun. Mac installed the hunting aperture, which has a larger hole for more rapid target acquisition. Peep sights with large apertures are quicker to get on target than regular notch sights, but the downside is you give up some precision to get the speed. I love the way an M1 carbine gets on target in an instant, but nobody will ever confuse it with a target gun because the large aperture reduces it to a minute-of-person weapon.
Accuracy
The first pellet Mac tried was the 7.9-grain Crosman Premier dome that’s usually one of the most accurate pellets in these multi-pumps from Crosman, Benjamin and Sheridan. But this day there was no joy as five pellets went into a group measuring 0.93 inches.
Crosman Premier lites were disappointing, producing a 0.93-inch group for five shots at 25 yards.
Next, he tried RWS Hobby pellets, which he also thought would be wonderful. They disappointed as well, with a five-shot group that measured 0.77 inches at the same 25 yards.
RWS Hobbys that usually do well were only so-so in the 397C. The group measures 0.77 inches.
Finally, Mac tried the pellet he likes the best for most air rifles in .177 caliber — the RWS Superdome. But try though he might, five of them grouped only 0.84 inches at 25 yards. Then, he had a thought.
RWS Superdomes that Mac likes didn’t do so well, either. This group measures 0.84 inches at 25 yards.
Inspiration!
Remember that forearm that moves on every shot? Mac noticed it, too, and was holding the rifle with his off hand close to the triggerguard, the way you’re supposed to hold a breakbarrel. He decided to throw caution to the wind and rest the rifle with the forearm lying on the flat of his palm. He just knew that the moving forearm would throw him off, but he tried another five RWS Superdomes and discovered the secret. That’s the perfect way to hold this little carbine! Five pellets went into 0.24 inches at the same 25 yards.
Mac discovered the secret hold! Resting the forearm on the flat of his off hand made this spectacular five-shot group with RWS Superdomes. It measures 0.24 inches between centers.
What this test tells us is that conventional wisdom isn’t always right. This reminds me of the time when I decided to hold my Beeman C1 carbine with a super-light hold to see how bad it would group and wound up discovering what I now call the artillery hold!
The bottom line for this little gun is that Mac loves it. He likes it most for its size and weight, and it’s the gun he most often hands to guests when they want to do a little shooting. Offhand, it shoots much better than these groups might suggest, and Mac doesn’t worry about the loss of velocity. As long as everyone has a good time and can hit the targets, everything is fine.
Benjamin 397C: Part 2
by B.B. Pelletier
Photos and tests by Earl “Mac” McDonald
The Benjamin 397C (right) is smaller than the 397 long gun.
We’re continuing our look at the Benjamin 397C that we started recently. It seems this model caught a lot of people off their guard, as the responses agree that not many people were aware it had even been made. In Part 1, I made reference to a comparison between this carbine and the 397 long gun, but I hope you understand that Mac is testing just this one gun. I’ll refer to the 397’s performance through the published specs and what I know of the gun. I invite any readers to add their comments as well.
Beautiful wood
Milan commented on the fine wood of the 397 rifle shown in Part 1, and I guess I should have said more than I did about it. Benjamin traditionally bought the wood for their rifle stocks from Stover, Missouri, and lucky owners often got beautiful stocks through the luck of the draw. The factory never made any attempt to segregate the wood by grain pattern.
I owned one Sheridan Silver Streak with a gorgeous crotch grain stock that would have added 50 percent to the price of any firearm it had been on. The wood on my current Blue Streak is pretty nice, too. So, good wood goes hand-in-hand with both the Benjamin and Sheridan names.
Velocity day
Today is velocity day, and it’s when we find out what has been sacrificed to shorten this carbine. Mac did several tests to help us understand how the multi-pump powerplant works. For starters, he pumped the gun different numbers of strokes and obtained the average velocity for each set between 2 pumps and 8. Let’s begin there.
The pump lever must be pulled down and forward like this for every pump.
All the following shooting was done with 7.9-grain Crosman Premier pellets in .177 caliber.
|
Pumps
|
Velocity
|
Low
|
High
|
Spread
|
|
2
|
325
|
318
|
331
|
13
|
|
3
|
407
|
401
|
412
|
11
|
|
4
|
466
|
462
|
471
|
9
|
|
5
|
511
|
509
|
513
|
4
|
|
6
|
544
|
538
|
549
|
11
|
|
7
|
576
|
573
|
582
|
9
|
|
8
|
596
|
593
|
598
|
5
|
We can learn some things from this data. First, notice that as the number of pumps increases, the velocity jumps get smaller. This demonstrates the diminishing returns that are common to all multi-pump pneumatics.
Another thing to take away from this is that the rifle is more stable at certain numbers of pumps than at others. Five pumps, for example, vary by only four feet per second across all ten shots, while six pumps vary by almost three times as much. What you can learn from this is that each rifle is very particular in how it behaves and you really need to know your rifle well. However, I’ll let you in on a little secret. In all the testing of both Benjamin and Sheridan multi-pumps that I’ve done over the years, I’ve found that five pumps is sort of a magic number for all guns. Fo some reason, they all seem to do well with five pump strokes.
And another thing. If Mac didn’t have a chronograph, none of this testing would be possible. Just one more useful thing you can do with them.
The last thing we can learn from this data is that a ninth pump stroke is probably not going to give any more velocity than eight strokes. In fact, it’s more than likely that the ninth stroke will actually make the rifle shoot slower than it does on eight. You can see that coming by looking at how close the average velocities are between seven strokes and eight. There’s an increase of only 20 f.p.s., while the difference between three and four pump strokes is 59 f.p.s.
What about nine pumps?
So, should you even try a ninth stroke? The answer depends on the gun. Most guns will not shoot any faster on nine pumps than they do on eight, but a few will. The gain might only be five f.p.s., but it will be a gain, nevertheless.
Most rifles will not increase, though, and after the shot when they’re cocked and fired again without pumping any additional times, you’ll hear some air exhaust. So, the ninth pump stroke was a waste of energy.
Bear in mind that the higher number pump strokes put a greater strain on the pump mechanism of the earlier ones because of the additional effort that’s needed. These guns have been designed to last virtually forever on eight pump strokes, but as you exceed that number the additional wear will cause them to wear out. When I was a kid, I used to hear adults brag about how they pumped their old Benjamin rifles up 30 times and they shot just as hard as a .22 rimfire. That’s hogwash! I can prove they won’t work that way, and if they really did pump their guns 30 times, which is next to impossible, they probably broke them.
Mac did pump his gun nine times for this test and he found that the velocity did go down by a few f.p.s. He didn’t keep a record of how much it dropped, so I can’t tell you that, but the rifle did exhaust air when it was cocked and fired again without pumping it again.
Velocity test
For this test, Mac started all over again. He didn’t re-use the velocity from the first test. This test was done at 8 pumps for every shot.
This time, Crosman 7.9-grain Premiers averaged 595 f.p.s. and ranged from 593 to 598, for a spread of five f.p.s. At the average velocity, the muzzle energy is 6.22 foot-pounds.
RWS Hobby pellets averaged 631 f.p.s., ranging from 626 to 638 f.p.s. That’s a spread of 12 f.p.s. The average muzzle energy was 6.19 foot-pounds.
RWS Superdomes averaged 596 f.p.s., with a spread from 592 to 602 f.p.s. The average energy was 6.54 foot-pounds.
Well, that should settle the question of what happens when a pneumatic is shortened. The velocity drops as the barrel gets shorter. The longer 397 rifle would get between 725 f.p.s. and 775 f.p.s. with 7.9-grain Crosman Premier pellets; and at an average of 750 f.p.s., the energy would be 9.87 foot-pounds. That gives you a good comparison between the long gun and the carbine.
Some readers have commented that the Benjamin 397 is already a smallish air rifle and wondered if it is really necessary to make a carbine out of it? I guess that’s a good question, because the longer gun has been in production for almost two full decades while the carbine lasted only four years. But Mac insists this is a very handy airgun, so I guess it’s one of those personal taste choices. If you look at the photo at the top of this report, you’ll note that even the pull length has been scaled back by an inch, so the carbine is undoubtedly best suited to shooters who either want or don’t mind a short-pull rifle.
Benjamin 397C: Part 1
by B.B. Pelletier
Photos and tests by Earl “Mac” McDonald
Today, we’ll begin a look at a strange duck. It’s an airgun model that is still current, but this variation is a relatively little-known offshoot that, because of its nature, is a completely different airgun. I’m referring to the Benjamin 397C. I linked to the Benjamin 397, which is the parent model and is still available for sale, because the “C” or carbine version of this multi-pump pneumatic isn’t made anymore. It was made and sold between 1994 and 1998, but not a lot of them were made. That’s the gun we’re studying today — the 397C that’s different than the longer 397, as this report will show.
The Benjamin 397C (right) is noticeably shorter and smaller than the 397 long gun. It’s three inches shorter and more than a full pound lighter than the rifle we know today.
Mac bought two brand new 397Cs at an airgun show several years ago. He has since gotten rid of one, but he holds on to the other because he’s grown to like it so much.
The carbine is 33 inches overall with a 16-inch barrel. The length of pull is a short 12-1/4 inches, but it’s comfortable for most adults in the offhand position. It weighs 4 lbs. 4 oz.
Design limitations
Because the 397C is a carbine and must be shorter than the long gun model, by definition of what a carbine is, it must also suffer the limitations that come with it. As regular readers of this blog know, pneumatic guns derive their power partly through the length of their barrels. Just as in the 19th century, a firearm rifle with a longer barrel was often more efficient and got more power from the same load than a shorter rifle when all things were equal, so any pneumatic will suffer from a power loss when its barrel is shortened. This is one time when physics will not give in to design.
Additionally, the pump mechanism and air reservoir were also shortened to make this carbine, so these two facts will affect performance as well. The bottom line is: don’t shorten the barrel if you want to get maximum efficiency from a pneumatic powerplant, anymore than you would shorten the barrel of a black powder rifle and not expect a similar power loss. Heck, for the same reason, the U.S. Army has discovered to its chagrin that the compact M4 carbine hamstrings the performance of the 5.56mm round that’s standard in the M16.
Design benefits
On the other hand, carbines are much handier to hold and to use. Mac pointed out that his 397C is a delightful airgun that he pulls out often when guests come over to shoot. Everybody likes the compact, light feel of the gun; and until you shoot it over a chronograph, you don’t notice the power loss. All things considered, Mac likes the carbine size over that of the full-sized rifle.
Because it comes from an older period in the life cycle of the 397, this carbine has the rocker-style safety that has a tab on either side of the receiver. It’s called a rocker safety because when the action is out of the stock you can see that the safety mechanism rocks from side to side as the Safe and Fire tabs are pressed.
The 397C has the old-style rocker safety that shooters love.
Like all other Benjamin pneumatics, the 397C is almost completely ambidextrous. The bolt is on the right side and cannot be switched, but the gun’s simple lines and the way the safety works combine to make it easy to operate from either side.
Like the full-sized 397, the carbine is recommended for a maximum of eight pumps and no more. Being a multi-pump, it can get along with fewer, depending on the situation. Three pumps for indoor target practice at close range and five if you want to shoot farther. Mac measured the effort required for the pump strokes and found that it takes 10 lbs. at stroke number two, 18 lbs. at stroke four, 24 lbs. at stroke six and 30 lbs. at stroke eight. That makes it somewhat easier to pump than the full-sized rifle, which requires about 35 lbs. for the eighth stroke. Of course, that means that less air is being compressed with every stroke.
Williams peep sight
Many of you know that Mac likes peep sights on his rifles, and Benjamin multi-pumps are made at the factory to accept them. When he purchased the gun, it had the Williams peep sight that is made specifically for Benjamin and Sheridan air rifles.
The Williams receiver sight is specially made to mount on the Benjamin and Sheridan pneumatics.
Two maintenance procedures
One thing the readers of this blog should have learned by now is that most CO2 and pneumatic guns require frequent oiling to keep the interior seals fresh and doing their job. But a quirk of marking on the rifle confuses many owners. The air intake hole has the words AIR HOLE DO NOT OIL stamped next to it, and many owners assume that means they are not to oil the rifle at all. In fact, oiling is one of two maintenance procedures that keeps the rifle operating for many decades. But you don’t oil through the small air hole. Instead, you extend the pump handle as far as it will go, which draws out the pump piston head as far as it can come. The pump head gets the oil. Three or four drops of Crosman Pellgunoil on the pump piston head every six months will keep the rifle working properly for a long time.
When the pump handle is opened all the way, the pump piston head comes as far out of the pump mechanism as possible without disassembling the airgun. Put three or four drops of Crosman Pellgunoil on the piston head at the end of the pump slot and then work the pump handle back and forth to spread the oil to the inner walls of the compression chamber.
The second maintenance procedure for this rifle is to always store it with a pump of air in the gun. That keeps both the inlet and firing valves shut against airborne contamination, and the seals will stay fresh for many years.
Mac promised to test both velocity and accuracy for us in the weeks to come. We’ll have a chance to look at this less-common type of Benjamin pneumatic and compare it with the longer rifle of today.
The 397C is another example of a rare type of airgun that’s still relatively unknown and still available for a good price. While it may not be your cup of tea, it gives us all hope that the field of airgun collecting is not just reserved for those with deep pockets and access to vintage airguns.
Webley Alecto – Part 4
by B.B. Pelletier
Webley Alecto
Well, today’s the special fourth report that I promised you. Last time, I said I wanted to try the pistol with hunting pellets on maximum power because of the showing I got with Beeman Kodiaks on three pumps. That’s what today is all about.
Again, I’ll tell you that these are 5-shot groups simply because the Alecto is so darned hard to pump 3 times. Ten-shot groups would have worn me out.
The trigger is the biggest drawback to this pistol. It’s a single-stage pull that doesn’t work for accurate shooting. The stage is heavy, long and creepy with an indistinct release. If the pistol had a better trigger, I think I could have done better with it. It needs a nice crisp two-stage trigger.
Accuracy test
I tested the gun supported from 10 meters. I used a two-hand hold, which is uncharacteristic for me, but necessary with the Alecto because the pumping effort left my shooting arm weak. My forearms rested on the bag, and the pistol was held by only my hands. It touched nothing else.
I changed the lighting during the test, so a couple pellets were shot a second time to ensure they got every chance to excel with the new lighting. The first arrangement of the light was obscuring the left side of the rear sight, so I moved it for a clearer sight picture.
Beeman Kodiak HP
The first pellet tested was the Beeman Kodiak HP, a new hollowpoint pellet. In .177 caliber, this lead pellet weighs 10.34 grains. In the Alecto, they were all over the place, grouping larger than two inches at 10 meters, so I cannot recommend them for this gun.
JSB Exact 10.2-grain dome
The JSB Exact 10.2-grain dome was pretty accurate in the Alecto. Because I changed the downrange lighting, I tested this pellet twice. Once I got a group about .75 inches for 5 and the second time the group was just over an inch. That seems like consistent performance to me.
This is the better target for the JSB Exacts. The group is just smaller than .75 inches.
Crosman Premier heavy
Next, I tried Crosman Premier 10.5-grain pellets. They grouped about as good as the JSBs.
Crosman Premier heavy pellets made this one-inch group at 10 meters.
RWS Supermags
Someone suggested that I test the RWS Supermag pellet in the Alecto, because, at 9.3 grains, they have the dual advantage of weight and the wadcutter shape that hunters like for close shots. When I shot them, they produced a teaser group in which 4 shots are in a tight cluster of just over a half-inch, but the fifth shot opens the group to double the size. I would say that you should put Supermags on your short list of pellets to try.
What a tease! Four RWS Supermags went into such a tight group, then one opened it to twice the size.
Air Arms Diabolo Field dome
Talk about teasing, the Air Arms Diabolo Field dome pellets did exactly the same thing. Four shots in just over a half inch then one stray that more than doubled the group. These should be on your list to try, as well.
More teasing. Air Arms Diabolo Field domes made this tantalizing group.
H&N hollowpoint pellet
The best showing with the Webley Alecto came with the new H&N hollowpoint pellet. At just 7.1 grains, this pellet is light and fast. In the Alecto, it’s the best pellet I tried. The 5-shot group is just over six-tenths of an inch in size, and I didn’t do anything different. I shot a second group just to be sure. While it was a little larger, it wasn’t more than three-quarters of an inch. That’s superior performance from this new hollowpoint.
Best group of the session came from the H&N hollowpoint.
Bottom line
It was well worth a second look at the accuracy of the Webley Alecto. We know it’s useful both for target work and hunting. Three pumps is hard work, but this pistol can deliver the results many airgun hunters have been waiting for.
Webley Alecto – Part 3
by B.B. Pelletier
Webley Alecto
Well, I think we have another classic air pistol on our hands. Today, I’ll test the accuracy of the Webley Alecto — and I’m impressed with it.
I realize it’s been a long time since the first two parts of this report, but you can use the links to go back and read what I learned. The Alecto seems very robust. I would have no problem accepting it into my collection.
Because the gun can be shot with a single pump, as well as two and even three pumps, I had to test it differently than any other air pistol. And, I shot 5-shot groups instead of 10-shot groups, just because the pumping made each shot take so long to prepare.
I shot at 10 meters and used a rest because I don’t have the arm strength yet to shoot this pistol one-handed. I experimented with different holds and lighting, and discovered something very interesting about the pistol. It is most accurate when shooting wadcutters on just one pump. When you pump it more than once with target pellets, the shot group opens up dramatically.
I expect this is due to the gun needing a new holding technique for two and three pumps, just because of the dynamics of the powerplant. On one pump, it acts just like a single-stroke pneumatic; but on two and three pumps, it acts like a multi-pump pistol. There’s recoil and movement to contend with.
One pump
Like I said, the pistol acts like a single-stroke on one pump of air. In fact, it’s even easier to pump than either the Beeman P3/P17 or the Gamo Compact.
The first pellet I tried was the H&N Finale Match Pistol. When fired by a single-stroke, they turned in a 5-shot group that looks like it was shot by a target pistol.
On a single pump, the Alecto shot H&N Finale Match Pistol pellets like a 10-meter gun.
Next, I tried RWS R10 pellets, which I assumed would shoot just as well. However, they did not. Even though my hold was just as good as before, the R10s opened up.
RWS R10 pellets scattered more with the same tight hold on one pump.
Two pumps
On two pumps, the H&N Target pellets opened up quite a bit. I didn’t believe it, so I shot several groups. The one below is representative of what happened.
On two pumps, H&N Finale Match Pistol pellets opened up.
The R10 pellets also opened up on two pumps, though not quite as much as the H&Ns. If this were a firearm handled, I would think the bullet was going too fast for good accuracy.
RWS R10 pellets also opened up on two pumps
Three pumps
I didn’t try RWS R10s on three pumps, but I did try H&N Match with three. They opened even more to my surprise.
On three pumps, the group with H&N Finale Match Pistol pellets was quite large, if the one hole at the bottom is considered.
Following the three-pump target, I shot another one-pump target with H&N pellets and got essentially the same group I showed before with one pump. So, the gun really likes a single pump, but with wadcutters it doesn’t seem to like more than one.
Then, I remembered that I’d promised one of our readers that I would also shoot the gun with Beeman Kodiaks. It’s a powerful air pistol, after all. I decided to go straight to three pumps for this, as the Kodiak is a very heavy pellet.
Beeman Kodiak Extra Heavy pellets look promising on three pumps.
And the results tell me that we need a part 4 to this test. I need to test this pistol with other domed hunting pellets to see what kind of accuracy potential there is on three pumps.
I must remark that one pump is very easy with the Alecto. Two pumps begin to get hard and three pumps is a real strain for me right now. But, if I were a hunter, I guess I would do whatever it took to get the job done. The pistol certainly wants to do its part.
