Posts Tagged ‘Crosman Premier pellets’
by Tom Gaylord, a.k.a. B.B. Pelletier
Today, I’ll report the velocities I got with the new AirForce Condor SS rifle with Spin-Loc tank, as well as the shot count per fill and some other interesting things. Yesterday, I spent some time informing you of how the baffled silencer system works in this rifle. Today, that becomes important to understand.
Before we begin, let me clear up some things. Blog reader RidgeRunner thought the reservoir of the Condor SS looked smaller in the photo than the old reservoirs on the other two rifles. It isn’t. It is exactly the same size. The foam that surrounds the tank has changed, and that might give the illusion that new tank is shorter, but that’s just an illusion.
Blog reader Bob from Oz asked for a diagram that shows the flow of air because he was confused by my textual description. That’s where the photo of the silencer parts comes in. The end of the barrel, the true muzzle, is buried deep inside the frame of the rifle. The frame is tubular in front, and many people might think that it looks like a bull barrel, but it’s actually a hollow tube that has an inside diameter of one inch. The baffles fit inside that hollow tube exactly as shown in the photo, except that they are touching each other when they’re installed, so they’re not spread out like they appear in the photo.
When the pellet and compressed air exits the muzzle of the barrel (deep inside the tubular frame of the gun), it passes through the first baffle and much of the air is stripped off. It passes through the open slot of the baffle and is deflected backwards by the wide flange of the next baffle. Then, it passes back through the holes in the front barrel bushing and into the open space between the barrel and frame behind the front bushing.
As the pellet passes through each baffle more of the compressed air gets stripped off and reflected backwards. This all happens in miliseconds and the air is still under pressure, so it eventually comes out the end cap of the rifle.
Why am I telling you this?
You have to understand how this works, or nothing I say will make much sense. The key to quietness is the volume of empty space inside the frame of the gun and the length of time it takes the compressed air to exit the gun. You don’t notice anything, of course. You shoot and hear the report at the instant of firing. But there really is a small lag time, during which the compressed air expands and loses its energy. That energy is what makes the noise, so the greater the expansion, the less noise there is. And the less compressed air that’s used with the shot, the lower the noise will be when everything else remains the same.
I told you this because, when I began testing the Condor SS for velocity, I was surprised by the noise. I was testing inside my office, which is 12 by 15 feet, and the last time I heard the rifle was outdoors back in November of last year. I knew this gun I was testing was louder than what I’d heard back then. So, I went to AirForce yesterday and we conducted some tests to determine where the production Condor SS is sound-wise. I’ll get to that after we look at the velocity, so let’s do that right now.
Like all the sporting precharged rifles AirForce makes, the Condor SS has adjustable power and interchangable barrels. There’s no way I can test every possible combination of pellets, calibers and power settings, so I selected spots in the power spectrum that I’ll report today. I will report each pellet at all the power settings and give you the shot count for each one.
Eun Jin domes
The first pellet I tested was the Eun Jin 28.4-grain dome. While there are heavier pellets that will generate greater power in .22 caliber, I believe this one will do well in the accuracy test, so it’s a reasonable top-end pellet to test. On the maximum power setting, this pellet averaged 892 f.p.s. I shot it 20 times and the high (shot 3) was 912 f.p.s. The low (shot 20) was 814 f.p.s. Yes, that is a 98 f.p.s. spread; but out to about 35 yards, this pellet will hold zero for those 20 shots. If you plan on shooting at 50 yards and farther, stop at around 10 shots. Your average then climbs into the low 900s and the max spread is less than 30 f.p.s. At the average velocity for the 20 shots, this pellet generates 50.19 foot-pounds of energy at the muzzle.
The power band is more or less a straight declining number from start to finish. Starting at 3,000 psi, you finish at 2,200 psi. A Hill pump then takes about 100 strokes to fill the tank again. So, there are 5 pump strokes per shot on max power.
The rifle was very loud, so I told Edith to change the sound rating in the description to a 4 because this gun is louder than a Sheridan Blue Streak on 8 pumps. It’s quieter than a Condor running at the same power, but still loud enough to notice. In fact, when I was testing the velocity in my office (with the door closed), Edith was in the living room and thought I was shooting a Quackenbush big bore because it was so loud.
Now, let’s look at the performance of the same pellet at different power settings.
On power setting 10, there were 20 total shots at an average of about 878 f.p.s. (48.63 foot-pounds).
On power setting 6, there were 22 shots at an average 868 f.p.s. (47.52 foot-pounds).
On power setting 4, there were 23 shots at an average 858 f.p.s. (46.44 foot-pounds).
On power setting 2, there were 25 shots at an average 830 f.p.s. (43.45 foot-pounds)
The power spreads from the first shot to the last were closing up as the power was dialed down; but even at setting 2, there was still 80 f.p.s. variation, start to finish. The beginning and ending air pressure was always the same for each string. Even on the lowest power the rifle sounded just as loud.
Then, I tried the Crosman Premier pellet that weighs 14.3 grains. The Condor was the first air rifle to get this pellet supersonic in .22 caliber. In the Condor SS, the average on high power was 1076 f.p.s. It ranged from a low of 1029 f.p.s. to a high of 1117 f.p.s., so, once again, a large spread. At the average velocity, this pellet generates 36.77 foot-pounds of energy at the muzzle. And there were the same 20 shots per fill, with the same starting and ending air pressures. There was no noticeable difference in the report between this pellet and the Eun Jin.
On power setting 10, there were 20 shots at an average of about 1067 f.p.s. (36.16 foot-pounds).
On power setting 6, there were 22 shots at an average 1062 f.p.s. (35.82 foot-pounds).
On power setting 4, there were 23 shots at an average 1033 f.p.s. (33.89 foot-pounds).
On power setting 2, there were 25 shots at an average 1010 f.p.s. (33.70 foot-pounds)
As with the heavy pellets, the power spreads were closing up as the power declined; but even at setting 2, they were still 60 f.p.s. from start to finish. The beginning and ending air pressure was always the same for each string. Even on the lowest power, the rifle sounded just as loud.
JSB Exact Heavys
Next, I tried the 18.1-grain JSB Exact Heavys. I expect this pellet to be matched well to the power of this new rifle. On maximum power, they averaged 1004 f.p.s., which generates 40.52 foot-pounds of muzzle energy. The high was 1059 f.p.s., and shot 20 was 962 f.p.s. I still got 20 shots per fill, and the muzzle report was identical to the others.
On power setting 10, there were 20 shots at an average of about 988 f.p.s. (39.24 foot-pounds).
On power setting 6, there were 22 shots at an average 981 f.p.s. (38.69 foot-pounds).
On power setting 4, there were 23 shots at an average 970 f.p.s. (37.82 foot-pounds).
On power setting 2, there were 25 shots at an average 966 f.p.s. (37.51 foot-pounds)
Notice that these pellets seemed to do very well on the lower power settings. That is important because the shot count increases with very little loss of power. The total velocity spread on setting 2 was 69 f.p.s. I think this may be the best pellet for this rifle, but accuracy testing will have to prove it.
The last pellet I tested was the Beeman Kodiak that weighs 21.1 grains in .22 caliber. Many will select this pellet for a powerful rifle like the Condor SS. On the maximum power setting, these pellets averaged 970 f.p.s. The high was 1017 f.p.s. The low was 908 f.p.s. Like the other 3 pellets tested, a large velocity spread over the 20 shots; but as I pointed out before, out to 35 yards it won’t make much difference. At the average velocity, this pellet generated 44.09 foot-pounds of energy at the muzzle.
On power setting 10, there were 20 shots at an average of about 965 f.p.s. (43.64 foot-pounds).
On power setting 6, there were 22 shots at an average 952 f.p.s. (42.47 foot-pounds).
On power setting 4, there were 23 shots at an average 936 f.p.s. (41.06 foot-pounds).
On power setting 2, there were 25 shots at an average 920 f.p.s. (39.67 foot-pounds)
Summary of power performance
The Condor SS I’m testing seems to work best at power setting between 4 and 10, with the lower setting being better. The shot count increases, and the velocity spread gets a little tighter, plus not much power is lost. Let’s keep that in mind, and I’ll get back to it in a moment.
Sound testing at AirForce
I took my rifle out to AirForce Airguns and tested it against a production gun, another gun that had a pre-production prototype barrel and a .22-caliber Benjamin Marauder. I had said in Part 1 of this report that the Condor SS set on maximum power was no louder than the Benjamin Marauder when I saw it shoot last November. The one I now have for testing certainly seems to be louder.
We shot outdoors but next to the steel building, so there was some sound reflection from the building walls. Clearly, my Condor SS is just as loud as the current production gun, and both are louder than the Benjamin Marauder dialed up to its maximum power. But here’s the difference. The Benjamin Marauder shot Beeman Kodiaks between 801 f.p.s. and 828 f.p.s., and both Condor SS rifles shot the same pellet at an average 920 f.p.s. when set on power setting 2. So the Condor SS is putting out about 40 foot-pounds when dialed down low, and the Marauder is putting out around 30 foot-pounds with the same pellet when it’s adjusted as high as it will go. That’s a big difference.
So, why was the Condor SS I had heard back in November so much quieter than this one? Well, for starters, back then the baffles had smaller holes through them. Now, they’re able to safely handle calibers .20 through .25; but back then, they were still experimenting with the hole size. Also, the barrel in my test rifle is 16mm diameter. The prototype rifle had used a 12mm diameter barrel; so AirForce installed a 12mm diameter barrel in their production rifle that we tested yesterday, and the sound went down a little. The 12mm barrels are being processed now for production.
Then, we installed a standard SS tank on the Condor SS that now had the 12mm barrel and dialed the power down to 838 f.p.s. with the Beeman Kodiak pellets. That was as low as we were able to go when the 3,000 psi fill was fresh. Now, the Condor SS was only a little louder than the Marauder that was shooting just a little slower. We shot them side by side several times to make sure. There’s a difference you can discern when testing side by side, but outdoors it isn’t that great.
Remember, this is shooting outside but close to a building, and the standard tank is being used instead of the High-Flo tank that comes with the rifle. You can buy a standard tank as an accessory, but they aren’t going to sell one with the rifle instead of the High-Flo tank, so don’t even ask!
As far as the Spin-Loc tanks are concerned, they’re the new design. Pyramyd Air has opted to phase out the version with the old-syle quick-detach tank and stock only the versions with the Spin-Loc tank. The quick-detach tank that screws in is also available as an accessory in both the standard and High-Flo configurations.
Observations so far
Wow! This has to be one of the longest reports I’ve ever written. And the first part of it was yesterday, in Part 3. I hope this addresses your concerns about this rifle, and that you now clearly understand what you’ll receive when you order a Condor SS. It’s quiet for the power it generates, but it’s not whisper quiet like I originally said.
There’s still so much ground to cover with this test rifle. Accuracy testing comes next at 25 yards and then 50 yards. And after that, I’ll install a standard tank and do today’s test again. Stay tuned!
by Tom Gaylord, a.k.a. B.B. Pelletier
Today, I’ll start testing the new AirForce Condor SS rifle with Spin-Loc tank. I’ve been waiting a long time for this test, because it affords us the opportunity to look at so many new things from AirForce Airguns. Not only will we get to see the new baffled silencer system, we’ll also get another look at the new trigger and safety on which I reported back in January. I linked to that report, above, and labeled it as Part 1 so you can get a better look at the new trigger by reviewing it, though I’ll continue to make comments on the trigger as this report unfolds. We’ll also get a look at the new Spin-Loc tank that allows filling without removing the tank from the gun. There’s a lot of ground to cover, so let’s begin.
The rifle I’m testing is in .22 caliber, which I believe is the best caliber for all AirForce rifles. I won’t give the serial number because this rifle is mine. It’s not going anywhere after this report is completed. Don’t worry — they’ll make more!
What is the Condor SS?
AirForce Airguns is an American manufacturer based in Fort Worth, Texas. They make all the parts of their guns except for the barrels, which they source from Lothar Walther, the air tanks on many of the sporting models and the synthetic parts. Although shrouded barrels are commonplace in 2013, it was AirForce that introduced them to the market back in 2001 with their Talon SS.
In 2004, they started production of the Condor, one of the most powerful smallbore air rifles the world has ever seen, and one that still gets more shots per fill than any of its competition. Generating 65 foot-pounds of energy in .22-caliber, the Condor is a pellet rifle whose muzzle energy equals the standard speed .22 short rimfire cartridge. Only the diabolo design (wasp waist and hollow, flared tail) of the pellets it shoots prevents it from shooting as far as the rimfire. The Condor gave airgunners a rifle with .22 rimfire power and reasonable downrange safety at the same time.
These are all precharged pneumatic (PCP) airguns. Their butt reservoirs are filled to 3,000 psi (nominally — each gun may be a little different) and fired until they fall off the power curve at lower pressure. A Condor will get up to 20 powerful shots on a fill, and a Talon SS will get around 35-40 shots.
Shooters liked the SS for its quiet operation. When it was new, the SS was one of the quietest airguns in town that was also legal to own because it doesn’t have a silencer that can be installed on a firearm. And the Condor that can shoot a pellet through one and a half 2×4 boards delighted folks with power they’d only dreamed about. But the Condor was noisy, and the SS produced only about 25 foot-pounds of muzzle energy in .22 caliber. People wondered why AirForce couldn’t do both things — power without the noise.
The rifle we’re looking at in this report combines much of the power of the Condor along with the quiet of the SS. In fact, this rifle is even quieter than an SS. It’s as quiet as SS owners wish their guns were.
And, in response to customer requests, AirForce now offers the Spin-Loc tank that remains attached to the rifle, once installed. It has to, because it sports an onboard pressure gauge — a manometer — that customers also said they wanted. I’ll grant that this gauge is a handy thing since it lets you know the state of the fill the moment you grab the rifle. That’s very convenient when you pick it up after the gun hasn’t been used awhile. There’s no need to guess at the charge — it’s right there on the gauge. It was always easy to count your shots before; but when you set aside the gun for many days, you might not remember where it was in the fill. Of course, you could always top it off before shooting, which is what shooters did before the gauge; but now they don’t have to. The gauge tells them if there’s still enough air.
The Spin-Loc tank has to be installed with tools that come with the rifle. An Allen wrench loosens the single locking screw that allows the threaded bushing in the frame to turn freely. That bushing will join the tank to the frame. Don’t remove the locking screw — just loosen it so the threaded bushing can turn freely. A toothed wrench or spanner that comes with the gun can then turn the bushing to tighten it onto the tank. The tank itself cannot be turned much because neither the pressure gauge nor the male Foster fill nipple will clear the frame. So, the bushing has to be tightened onto the tank’s threads — drawing it onto the frame.
I have to say that it took me a couple tries before I got the tank threading straight onto the bushing. It’s a problem of controlling both the gun and the tank, so the tank’s threads do not start cross-threading. Both the bushing and the tank’s threads are steel, though, so the risk of damaging the threads is low. Just work carefully; and once the threads start to join, everything goes together easily.
Once the tank was on the gun, I adjusted the pull length by adjusting where the buttpad clamps to the rear of the tank. I noticed that the buttpad can also be flipped upside down, allowing it to extend lower for more contact with the shoulder, so I did that, too. In the end, I have the rifle set up for a 14-1/2-inch pull, which is ideal for me, and the buttpad is canted inward at the toe, which is how all my AirForce rifles are set up. There are several inches of adjustment with this pad, so fitting an adult shouldn’t be a problem. The picture at the top of this report shows the buttpad reversed like this.
New trigger and safety
I covered the new trigger and safety thoroughly in Part 1, but it’s new so I’ll mention it here. The trigger is 2-stage and not adjustable. I’ll give you the pull weight and critical data in the velocity test, which comes next, but we do know that it’s very crisp and stops after the sear is released.
The biggest difference in this trigger is that it cannot be uncocked. The gun, once cocked, must be fired. Since the Spin-Loc tank cannot be easily removed, the question becomes: Can you release the trigger without opening the valve? As it turns out, you can. Simply move the bolt a little forward so it isn’t pressed against the valve (which is referred to as the top hat), hold it there with your thumb and pull the trigger. Your thumb will catch the striker before it opens the valve very far, limiting the amount of air the gun fires. As convenient as this is, I would only do it with an unloaded (no pellet in the breech) gun that’s pointed in a direction that would be safe to fire. Because if you misjudge where the bolt has to stop, the gun could still fire a pellet.
The Condor SS comes with an 18-inch Lothar Walther barrel in your choice of calibers (from .177 through .25). Naturally, you can change the barrels as with all other AirForce sporting rifles, so you can own all 4 calibers for a fraction of what 4 complete guns would cost.
Ahead of the barrel is the system of baffles that make the SS what it is. I’ll show those in the next report, but there’s something that nobody has mentioned, yet. This rifle will also accept a tank with a standard valve; and if you use one of those, you’ll get twice the number of shots as you get from the Hi-Flo tank that comes standard on the Condor. And because of the 18-inch barrel, the gun will also be more powerful than a stock Talon SS. So, you’ll have great power and lots of shots! This is so intriguing that I’ll test it for you after I complete the full test of this gun as it comes from the factory.
Like all AirForce sporting rifles, this new one also has adjustable power. We’ll experiment with that when we test the rifle for velocity.
The Condor SS is made of aluminum, steel and some soft synthetic parts such as the grips and forearm. It has very straight lines, and the buttpad that drops down plus the raised scope rail make it quite easy to adapt to scope use. The accuracy is legendary, and we’ll put that to the test at multiple distances.
I’ve waited a long time to test this gun for you. So, sit back and enjoy this — it’s going to be a long ride.
by Tom Gaylord, a.k.a. B.B. Pelletier
This comment came in last week from our new blog reader Jim H, and I wanted to address it right away. It’s a good question for a new airgunner to ask, and it deserves a good answer.
“I’m new to the airgun side of things, so I have a lot of questions but here’s one that is really bugging me. I have read all of the reviews here by Tom and also the blogs over at that “other airgun retailer” written by Jack Elliot. One message that has come through loud and clear is that each gun will tend to like specific pellets and only experience will tell the shooter which one is best. What is the best approach for testing various pellets? Do you pick a velocity that you want to shoot at and then try all the pellets that will get you to that velocity range or do you simply have favorite pellet brands and types that you’ve come to love over the years and that’s what you go with? With the hundreds of pellets available out there, what is the ’short list’ of pellets that a newbie needs to start with?”
Several of you started to answer Jim in the comments section, so my answer comes a little late; but from what I’ve read, I’m telling him things that are pretty different from what all of you told him. He actually asked 2 different questions: 1. What is the best way to test a pellet? and 2. What is a short list of pellets to choose to test airguns? I took my direction for this report from his request for a “short list” for a newbie.
This will not be a very technical report. I’m not going to discuss pellet head sizes or skirt thicknesses, except where it affects the pellets I name. I have a short list for most of the airguns I shoot, and it’s not rigid. But it’s caliber-specific, and there’s also a small powerplant component to it.
Money is no object
I used to focus on the cost of pellets, but that was before discovering that hitting the target is far more important than saving money. If saving money is your principal goal, get a piggybank. I shoot for fun, and hitting the target is where the fun is. It costs no more to be accurate than it does to experiment by chasing the illusion of economy.
I must also say that I have more experience with pellets for rifles than for pistols. So, today we’re just looking at pellets for rifles. Let’s take a look at them.
For .177 rifles my short list is the following pellets:
Crosman Premier lites (brown box) springers and CO2
Crosman Premier heavies (brown box) pneumatics and CO2
JSB Exact RS (up to 12 foot-pounds)
JSB Exact Heavy 10.3-grains
H&N Baracuda and Baracuda Match
Beeman Kodiak and Kodiak Match
That is my short list. There are other pellets that are very accurate, but I find them to be more specific to certain guns. Please remember that this is not a popularity contest. If your favorite pellet didn’t make my list, don’t fret. I try other pellets all the time — these are just the ones I count on.
If you ask me why these pellets are on the list, it’s because they’re the ones that are the most reliably accurate. That’s my only criteria because if you can’t hit the target, nothing else matters.
The .20-caliber list is very short because there aren’t as many reliable pellets made in that caliber. The most reliable one is the Crosman Premier.
Other than that, I would try anything JSB makes, and that’s about it.
The quarter-inch caliber is another one with few good pellets. The two on my list have demonstrated they will deliver in all cases.
Benjamin domed (these have no name, but they are essentially a .25 caliber Premier)
JSB Exact King
I prefer domed pellets to all other shapes. They’re more accurate at long range and penetrate well. Wadcutters are good for distances under 25 yards but not for farther than that.
Pointed pellets, hollowpoints and lead balls
I have no use for pointed pellets of any kind. I’ve never found them to be accurate, and the slight advantage they have in penetration isn’t good if they can’t hit the target. Hollowpoints are a subject that need a blog report of their own. Lead balls are specialized for certain airguns and are not for most air rifles.
Pellets and power
As power goes up, the pellets should generally get heavier. And PCPs tend to do best with heavier pellets. CO2 guns are a lot like PCPs when it comes to pellets, so I consider them to be the same.
Other selection criteria
There are other selection criteria, of course. I’ve found certain pellets to sometimes be surprisingly accurate in certain guns, and that’s enough to keep me trying them in other guns — searching for more miracles. But the lists above are the tried-and-true performers that almost never let me down. That’s why they made my list.
The second question
The other question Jim asked was how to test pellets. I do it by choosing the most accurate rifle I have and shooting 10-shot groups with each pellet in which I’m interested. Do it that way, and pellet testing is easy.
I usually don’t express my opinions this strongly; but when it comes to picking a good pellet, I think it’s too important to let it slide.
by Tom Gaylord, a.k.a. B.B. Pelletier
This is Part 7 in this lengthy test series that looks at the effects of the rifling twist rate on both velocity and accuracy of a pellet rifle. Today, we’ll look at the 1:22 barrel, which means the pellet will turn once in each 22 inches of barrel it traverses. Of course, the Lothar Walther barrel in the .22-caliber AirForce Talon SS rifle I’m using is only 12 inches long, so the pellet doesn’t even turn one time before it leaves the muzzle, but that twist rate sets the pellet in rotational motion as it flies through the air to its target. The rotational speed will be less than what the 1:16 factory barrel imparts, and much less than the 1:12 barrel we have also tested.
Dennis Quackenbush made the two custom barrels I’m testing against the factory barrel with its 1:16 twist. So far, we’ve tested velocities with 2 different pellets at 3 different power settings for all three barrels (see Parts 2 and 3), and I did a short analysis of those tests in Part 4. Then, we tested the accuracy of the custom 1:12 barrel with both pellets at all 3 power settings at 10 meters, and again at 25 yards. Next, we did the same thing with the factory barrel.
Today, we’ll look at the accuracy of the 1:22 barrel with both pellets at all 3 power setting at 10 meters and again at 25 yards. In the next report, I’ll summarize the entire test to this point for you — comparing all 3 barrels for both power and accuracy. After that, I plan on testing all three barrels for accuracy at 50 yards. At that distance, the pellets will be spreading and accuracy benefits should show up vividly.
On to today’s test — the 1:22 twist-rate barrel.
First up was the 14.3-grain Crosman Premier pellet. I had to remove and remount the scope, and the pellets were now striking to the left and low of the bullseye, but I left it there because where the pellets land doesn’t really matter in this test.
Ten pellets made a group that measures 0.258 inches between centers. Besides being tight, it’s a very round group, indicating the pellet likes this twist rate and power setting.
Next came 15.9-grain JSB Exact pellets on zero power. They also made a round group, but it was larger, at 0.324 inches. This is still a very nice group, but not as nice as the Premier group on the same power setting.
Next, the power was dialed up to 6, and I shot a second group of Premiers. This time, the group was wider than it was high and measured 0.293 inches between centers. That’s smaller than the previous group of JSBs but slightly larger than the Premiers on the zero power setting.
Following that, I shot 10 JSB Exacts on setting 6. They gave a group that is more vertical and measures 0.309 inches between centers.
I noticed at this point in the test that both pellets were loading very easy into the breech. I wouldn’t call them loose — just very easy to load.
It was time to dial the power up to 10 and see what happened. Premiers went first, and 10 of them went into 0.288 inches. That’s just slightly larger than the first 10 on zero power.
And, finally, I shot 10 JSB Exacts at 10 power. They spread out more than expected, giving a group measuring 0.53 inches at 10 meters. That was by far the largest 10-meter group.
What I see here is that Premiers are very stable in the 1:22 barrel. There is little difference in group size at any power setting. JSB Exacts, on the other hand, get progressively worse as the power increases. If we see this much dispersion at 10 meters the difference should be even more visible at 25 yards.
First up at 25 yards was the Crosman Premier with the power set to zero. The 10-shot group landed very low on the target paper, and measured 0.671 inches between centers.
Next, I tried 10 JSB Exacts at the zero setting. They were horrible — making a vertical group measuring 1.949 inches between centers. I won’t shoot this pellet at this power at 50 yards because they would go off the paper!
Next, the power was increased to 6 and Premiers were loaded again. Ten of them made a horizontal group that measures 0.845 inches between centers.
Then it was the JSB pellet’s turn. Ten Exact Jumbos landed in 1.797 inches, which is a little smaller than the group when the power was set to zero. If I try to extend this pellet and power setting out to 50 yards, I’m very likely to get a 7-10-inch group.
Finally it was time to try the pellets on power setting 10. Here they would be traveling their fastest, which means the spin rate would also be highest for this barrel. According to the theory, the groups should get smaller.
Premiers went first, and 10 of them landed in a group measuring 1.082 inches between centers. That’s larger than both groups that went before. Since the velocity increased, the Premiers spread out. Interesting!
Finally, it was time to try the JSB Exact Jumbos on power setting 10. This time the theory did play out as expected, because 10 pellets made a group measuring 1.172 inches between centers. It’s smaller than the group from both of the lower power settings, and those groups decreased in size as the power increased.
Premiers behaved differently than JSB Exact Jumbos in this test. They did not become more accurate as the velocity increased, and I think I can suggest a reason why. JSBs are longer than Premiers. Premiers measure 0.269 inches in length, while JSB Exact Jumbos measure 0.296 inches in length. At their widest, which is the skirt, Premiers are 0.220 inches in diameter, while JSBs are 0.222 inches across. So, JSBs are longer than Premiers, in relation to their diameter, and that makes them harder to stabilize.
That was one of the problems I had with the .22 Hornet centerfire rifle I reported on last week. It shoots its bullets very slow, relative to other .22 centerfires, yet the twist rate is 1:16, where other .22 centerfires are 1:12, or in the very specialized instance of the .223/5.56mm, anywhere from 1:7 to 1:12. That’s why I’ve been writing about these rifles — so we can all gain an appreciation for how twist rates affect accuracy. The .22 Hornet can only do its best with short, fat bullets of relatively light weight. Now, you see the same thing in a pellet rifle.
Today, we see a very dramatic result of how the twist rate affects accuracy. We learned in our test of the smoothbore pellet gun that while a gun may be accurate at 10 meters, it may fall apart at 25 yards. Today, we see that in a rifle that has a very slow twist rate doing the same. If we wanted to use this twist rate, we would need to shoot only very short pellets so they could stabilize. See how it works?
Next, I’ll write up a summary article of the test to this point so we can get a grip on all the data that’s been generated. Of course, it’s all here for you now. All you have to do is go back and look at the results of all the testing to see how the twist rate affects both velocity and accuracy.
Following the summary report, I’ll test all three barrels at 50 yards.
by Tom Gaylord, a.k.a. B.B. Pelletier
This is the sixth part of a very long test in which we’re looking at the effects of the rifling twist rate on accuracy and velocity. If you have landed here and not read the first 5 parts of the report, I advise you to do so before reading today’s report because I’m not repeating a lot of what went into this test.
I’m using an AirForce Talon SS rifle in .22 caliber because it’s accurate and also because the barrels are easy to change. Dennis Quackenbush has made two barrels with twist rates of 1:12 and 1:22 for this rifle, but today I’m testing the Lothar Walther barrel that comes standard in the gun.
Today, we’re looking at the accuracy of the factory barrel that has a 1:16 twist rate. I’ll shoot 10-shot groups at 3 power levels with 2 different pellets at 10 meters and 25 yards. That means I’m shooting the rifle 120 times for today’s report. Some of you have wondered why it takes so long between reports — this is the reason.
What you’ll see in today’s report was actually shot on two different days because I cannot maintain concentration for 120 continuous shots. So, I shot the 10-meter targets on one day and the 25-yard targets on another. All shooting is off a rest, to take as much of the shooter out of the equation as possible.
First up is the 14.3-grain Crosman Premier pellet with the rifle’s power set at zero. Ten pellets made a group measuring 0.495 inches between centers. If you’re interested in the respective velocities of each pellet at the various power settings, you can find that in Part 2.
Next, I fired 10 15.9-grain JSB Exact pellets on the same power setting. The group measures 0.10 inches between centers. That’s for 10 shots! Don’t tell me that a Talon SS isn’t accurate!
Next, the power was dialed up to setting 6, and I shot a group of Premiers. To see how the power settings are calculated, look at Part 2. Ten pellets made a group that measures 0.404 inches between centers.
Then, JSBs were shot at the same power setting. This time, they landed in a group that measures 0.092 inches between centers. This is better than a lot of 10-meter rifles can do for 10 shots at the same distance. People will argue that they can do better, but it’s always a 5-shot group they show.
Now, THAT is a group! Best one of this test and better than many 10-meter target rifles, it’s 10 shots on 0.092 inches. It looks vastly smaller than the other small group above, but this one has more paper that closed back on the group than the first one.
Finally, we come to power setting 10. Premiers grouped 10 pellets in a tight 0.247 inches. This group is very round, indicating the barrel likes this pellet at this power level.
JSBs at power setting 10 finished the 10-meter testing. They landed in a group measuring 0.299 inches between centers.
Now it’s time to move back to 25 yards and test everything again. First up is the Crosman Premier at power setting zero. Ten made a 0.48-inch group.
JSBs came next. On power setting zero, they made a 0.571-inch group.
Then, the power was dialed up to 6, and Premiers were fired again. Ten went into a 0.654-inch group. That was the largest group fired with the factory barrel in today’s test. This group was also spread very horizontal.
JSBs made a 10-shot group that measured 0.569 inches between centers. This group was also horizontal in shape.
Finally, the power was dialed up to 10, and 10 Premiers were fired again. This time the group shrank to 0.329 inches. I call that a significant result; because not only is this group much smaller than the group fired on power setting 6 with the same pellet, it’s also very round and uniform. I think it shows that the factory barrel likes this pellet at power setting 10.
And JSB Jumbos at power setting 10 produced a group measuring 0.359vinches. That’s just slightly larger than the Premiers. I think the rifle really likes power setting 10. This group isn’t as round, but it’s clover-shaped, which is also good.
Interpretation of these results
I will hold off interpreting the results of all the testing until I’ve shot the 1:22 barrel at 10 meters and 25 yards, but something stands out in today’s test. At power setting 6 and 25 yards, accuracy went out the window. It got better at the low end of the scale and again at the high end; but for both pellets, power setting 6 didn’t seem to work well at 25 yards. Yet, at 10 meters, that setting and JSB pellets produced the tightest group of the entire test.
This is the kind of thing an owner has to do with his rifle with each pellet he plans to shoot. And it’s also why spending an inordinate amount of time examining one specific power setting is useless if you don’t know the big picture first. Look at the JSB target on the zero setting at 10 meters to see what I’m saying.