Penetration and Expansion Testing

[rsterne]

One last set of test for those interested in hunting with Non-PAL airguns.... I tested a variety of pellets in both .177 and .22, using a 2289 based rifle, pumped to give just over 400 fps with a 7.9 gr. pellet in .177 and the same velocity with 14.3 gr. in .22 cal.... Since we are mostly interested in how hollowpoint pellets might expand, I chose those velocities as representative of what they might arrive at 20-25 yards at when shot from a Non-PAL gun.... Here are the results, first in .177:



From left to right:
RWS Hobby 7.1 gr.
RWS Super HollowPoint 7.1 gr.
H&N Terminator 7.1 gr.
Crosman Destroyer 8.0 gr.
Crosman Premier Hollowpoint 8.0 gr.
JSB Exact Express 7.8 gr.
JSB Predator Polymag 8.2 gr.
Beeman Round 8.4 gr.
H&N Crow Magnum 8.8 gr.
H&N Baracuda 10.2 gr.
JSB Monster 13.5 gr.
H&N Rabbit Magnum 16.4 gr.

Not one single pellet expanded, they all looked like they just came out of the tin (except for rifling marks).... Now the .22 cal (photo to same scale):



From the left; H&N Crow Magnum 18.0 gr.
Bottom row, left to right:
RWS Hobby 11.9 gr.
RWS Super HollowPoint 14.3 gr.
Crosman Wadcutter 14.3 gr.
Crosman Premier HP 14.3 gr.
JSB Exact Express 14.3 gr.
Gamo Round 15.4 gr.
JSB Predator Polymag 16.2 gr.
JSB Exact Heavy 18.1 gr.
H&N Baracuda 30.9 gr.
JSB Exact Monster 25.3 gr.
H&N Rabbit Magnum 24.8 gr.

Again, not one single pellet showed any expansion.... I can say with confidence that in a Non-PAL airgun you should simpy use the pellet that is the most accurate for your gun, period.... The wadcutters left a slightly larger entrance hole and penetrated less.... The roundballs penetrated the greatest amount, closely followed by the round-nosed, and although I didn't test any pointed pellets, previous tests have showed little difference from a round nose of similar weight.... Heavier pellets tended to penetrate further that light ones, even though they were going slower....

One other thing should be obvious.... The .22 pellets generally penetrated further, and made a bigger wound channel.... Penetration in .177 varied from 13-22 mm (averaging under 3/4"), while in .22 cal it was from 19-29 mm (averaging over 1").... There is little magic in that, as at the same velocity, and being heavier, they have a lot more FPE, and hence a lot more punch.... That's not a lot of penetration to dispatch anything much bigger than a starling or a rat.... so if you're hunting with a Non-PAL airgun, take your best shot, within 25 yards, and be realistic....

Bob

[rsterne]

OK, so today I did more Non-PAL testing, in .22 cal, at a range of 25 yards.... I was using a 2289 tuned for 498 fps with JSB Exact RS 13.4 gr. pellets, and it shoots 485 fps with 14.3 gr Exact Express.... I didn't measure the velocity with lighter and heavier pellets, but they are what they are, just as they would be with any Non-PAL gun.... Since the soap was set up at 25 yards, I figured 1.25" of soap was enough to stop the pellets, but I very nearly got pass throughs with all of the JSB Exacts, and the H&N Baracuda, they all bulged the far side of the block of soap.... Here are photos of both sides of the block....





I "flipped" the photo of the back so that the pellets are in the same relative location in the block to make it easy to find them.... Here is a list of the pellets by number, with the penetration in mm:

1. JSB Exact RS Round Nosed 13.4 gr. - 34 mm
2. JSB Exact Express Round Nosed 14.3 - 35
3. JSB Exact Jumbo Round Nosed 15.9 - 36
4. JSB Exact Heavy Round Nosed 18.1 - 35
5. JSB Exact Monster Round Nosed 25.3 - 38
6. H&N Baracuda Pointed Round 30.9 - 37
7. RWS Hobby Wadcutter 11.9 - 20
8. RWS Super HollowPoint Hollow Point 14.3 - 23
9. RWS Super Dome Domed 14.3 - 23
10. RWS Super Point Pointed 14.3 - 26
11. Crosman Wadcutter Wadcutter 14.3 - 18
12. Crosman Premier HP Round HP 14.3 - 29
13. Crosman Premier Round Nosed 14.3 - 30
14. H&N Hollow Point Hollow Point 12.2 - 17
15. H&N Field Target Trophy Round Nosed 14.2 - 28
16. H&N Crow Magnum Hollow Point 18.0 - 17
17. JSB Predator Polymag Tipped HP 16.2 - 22

There are a few important observations to be made.... First, there is little difference in the diameter of the entry wound, regardless of the pellet type.... In fact, the slight cratering that appears around some of the holes appears to be related more to the impact velocity than the pellet shape.... There was no cratering observed in pellets over 15 gr.... Secondly, the penetration was mostly related to the shape of the pellet.... There was also a close correlation between the Ballistics Coefficient and the penetration.... The pellets that penetrated the furthest had good BCs and arrived at the target with the largest percentage of their FPE remaining.... This is very much "real world" testing at its best.... Here are photos of the wound channels of all the pellets tested....















Note that none of the pellets showed ANY sign of expansion when recovered from the soap.... Their killing power is strictly a function of how deeply they penetrated, as there is no significant difference in the shape of the wound channel.... I didn't test every pellet I had available, but I feel that the cross section of pellets tested tells the story well.... For example, there was no point in testing heavy hollowpoints that didn't expand at more than twice these FPE levels.... I didn't test any .177 pellets, as they didn't fare as well as the .22 cal pellets in previous tests at non-PAL velocities....

In conclusion, I am convinced that with the meager energy available in a non-PAL airgun, delivering as much of that energy as possible to the target is the most important consideration when hunting.... That means that .22 is far superior to .177.... It means that round-nosed pellets are superior to any other shape because of their better BC and superior energy retention.... None of the pellets show any expansion, nor does "shocking power" appear to be an issue, particularly when you consider that the wadcutters and hollowpoints arrive at the target with less FPE because of their poorer BCs.... There is little difference in the penetration of different weights of round nosed pellets because the heavier ones start out slower.... Some of the heavy pellets required more than two Mil-Dots of holdover at just 25 yards, compared to a 14.3 gr. pellet, so trajectory becomes a big issue.... That brings us down to a very few choices, and the top two are the JSB Exacts in 13.4 gr. and 14.3 gr.... Next would be the Crosman Premier 14.3 gr. (including the HP) and the H&N FTT at 14.2 gr.... If your gun shoots any of those accurately, I would stop looking.... The RWS "Super" trio (HollowPoint, Domed, and Pointed) also at 14.3 gr are the remaining group to try.... If you want to try something just a bit heavier, the JSB Exact 15.9 gr. and Predator Polymag 16.2 gr. would fill out the field.... I wouldn't go any heavier because of trajectory considerations.... Personally, the only time I would use a wadcutter (or any of the other pellets) is if none of the above are accurate in your gun, and then you must reduce the range accordingly....

Bob

[AirGunEric]

Where did you find the best melt-pour clear soap for the tests?

[rsterne]

I purchased from here.... http://www.newdirectionsaromatics.ca...ear-p-598.html

I purchased the 12-pack of 2 lb. bricks.... It takes two bricks to fill an 8 x 8 x 2 Pyrex dish or a 9 x 5 x 3 loaf pan.... You melt it in a double boiler....

This is another source.... http://secure.mycart.net/catalogs/ca...showprevnext=1

I don't know if it's "the best", but it can be remelted and repoured whenever you want.... I would imagine those two products are the same....

Bob

[Fastair]

Thanks for posting all the information Bob. This is a super post.

[Doc Sharptail]

This is great info! I don't know how I missed it.

The information on the powder .22's practically mirrors my field experience. There is an exception though- apart from the hollow points, I found the CCI short CB cap to be a clean taker of grouse. Identical to the 710 fps you mentioned. The bullets on these were soft- they easily marred with a finger nail, like the old 60-40 lead solder. I found them to be very accurate in guns that were marked s,l, lr.

The crow magnums in .22 would be worth investigating, for me...

Regards,

Doc Sharptail