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Posted: 4/18/2012 8:58:09 AM EDT
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I posted this over in GD originally because it contained several different subjects but I realized some of you guys may not look over there very often.
I've been working up a handload for my 10mm Witness and a 5.56mm SHTF load. Here is what I tested yesterday, thanks to Rifleguy81 and FightingHellfish. First the 5.56mm stuff: Temperature was approximately 60 degrees F. Chrono was about 6' from the muzzle. For comparison, one round of M855 was fired from each rifle. M855 from 11.5": 2,810fps M855 from 16": 3,153fps 65gr SGK over 24gr TAC (5.56mm pressure load): 16": 2,712fps 2,668 2,749 2,687 (error) 11.5": 2,514fps 2,553 2,539 2,496 2,471 I fired one from each into water jugs from about 20'. I was unable to find any significant pieces from the shot from the SBR but the one I fired from the carbine is pictured below. Recovered fragments weighed 53.6gr and the core measured .411". I did not expect fragmentation from this load but there it is. Despite not being able to recover anything from the 11.5" shot, I'm pretty sure it, too fragmented. If it hadn't, it should have stayed on a relatively straight path and been recovered. 
Now for the 10mm stuff: All velocity testing was done with 155gr GDHP and IMR 800X at the same distance and conditions as above. I did not have enough of the Buffalo Bore to shoot it over the chrono but others have confirmed their velocity claims of 1,350fps to be very close to actual. Because there was much less velocity gain going from 10.5gr to 11.0gr I decided to stick with 10.5gr as my defense load for now. Recovered fragments from the 180gr MT Gold bullet weigh 162.2gr. Core measures .66". And the 155gr GDHP Recovered bullet measures .915" and weighs 154.4gr. 9.0gr: 1,179fps 1,146 1,192 1,152 1,161 9.5gr: 1,260fps 1,217 1,206 1,208 1,237 10.0gr 1,269fps 1,285 1,284 1,315 1,265 10.5gr 1,362fps 1,374 1,391 1,374 1,361 11.0gr 1,392fps 1,365 1,439 1,377 1,413 180 gr Montana Gold: 
155 gr Gold Dot: 
Holy textbook perfect expansion, Batman! 
As O_P says: "Shooting stuff is fun." ETA: Shot a few more pistol rounds into jugs over the weekend. All I have is a pic of the .40 S&W right now but I might be able to get pics or video from some of the other guys that were there. We used Arrowhead water jugs, approximately 4.5" thick. We fired 9mm +P 124gr Gold Dot from a G19, .45 230gr Ranger from a commander length 1911, and .40S&W 180gr Gold Dot from a G22. All three penetrated EXACTLY three jugs, denting but not penetrating the plastic. The .45 made it "farthest," actually embedding in the plastic. A 158gr semijacketed soft point .357 round shot cleanly through six jugs, including some larger diameter gallon jugs. The .40 weighed 177.5 gr and measured 0.85" at its widest point. I hate to say it, but I have to question O_P's and Dr. Robert's standard of water representing 1.8-2 X the penetration of gel or tissue. Maybe it's the plastic walls that slow the bullet a tad but I doubt it. All three of the JHP loads we fired are well respected defensive rounds known to meet the FBI minimum. Just a little bit of Googling yields a multitude of calibrated gel tests involving the rounds in question, not to mention real world shootings. In our test, each round penetrated 13.5" of water, with just enough energy left to dent the plastic. This is not consistent with the 1.8-2X figure as that would have meant approximately 7.5" of penetration in tissue from every one of those three rounds. In reality, each of them get very close to the same penetration in calibrated gel as I got in water jugs. Now I'm not trying to say that water is a better test media at all. I'm also aware that JHPs will see their ideal expansion in water and that likely limits penetration. It may be correct that some bullets (FMJ, maybe) penetrate 1.8-2X as far in water as they would in gel or tissue but it seems pretty clear than not all bullets do. If anything, all I'm trying to say is that, while it is fun to shoot water and interesting to examine the recovered bullets, water is not a good predictor of terminal performance, not even in regards to penetration. 180gr .40 S&W: 
155gr from 10mm on the left, 180gr from .40S&W on the right: 
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| Thank you. Any thoughts on the discrepancy in penetration between mine and O_P's tests? He pointed out that if I didn't use denim (I didn't) the tests aren't standardized. I think it may be possible that the denim delayed expansion, causing the bullet to penetrate more deeply. Do you have any other ideas on what might cause the difference? |
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