This bullet trap is fascinating to a geek like me. I can’t wait each time to dig out the bullets and see what they look like.
I loaded up 50 rounds of .357 mag with #105, (lot # 71195) last week and launched them downrange today. #105 is supposed to be AA#5 equivalent. I found something interesting when I retrieved the bullets from my (shredded tire) bullet trap. The front driving band was gone because the nose had slumped back, shortening the bullet noticeably. I have never seen this before. I don’t think that this is caused by the shredded tire mulch, because it hasn’t happened with other bullets, and some 358156’s fired at the same time, with different, but top-end loads and similar Bhn didn’t show this. Of course, I could be wrong. I can't remember if I've fired the 358311 into the trap before.
"A" shows an unfired (but not a prime example) of the 358311. "B - D" shows the fired 358311's.
There was no leading, but primers were flattened on all but the lowest loads, with striated impressions of the firing pin bushing(?), or whatever that's called stamped on the primer. The lowest load was put together with the bullet crimped above the driving band, which is the only way to get the 1.590" OAL recommended. Brass dropped right out of the cylinder on the lower end loads, and had to be coaxed out with heavier loads.
.357 magnum R-P nickel plated brass, once fired
358311 RN 0.359” lubed with Felix lube...wheelweights, Bhn 14-15 on my Cabine Tree gizmo
CCI 550 magnum primers
Accurate Arms most recent load data for AA#5, lowest to nearly highest, 8.1 - 8.9 grains
Ruger Blackhawk (3 screw), bore size 0.357.5”
Also interesting was the nearly completely collapsed lube grooves, the severely pounded gas check base, and the lead smeared on the gas check of the 358156’s. (E, F & G) These were similar in hardness, and loaded pretty hot with WC820.
Here are some more retrieved bullets:
[edit: The 358439 is actually 358430!]
No slumping on the swc's, but they were fired with .38 Special loads. The 358439 does show a bit of slumping, so maybe it's a round nose phenomenon? (Actually the OAL of the fired boolit is only .002" shorter than an unfired one.)
I wasn't sure if the 457125's were going to be able to engrave properly in my Trapdoor's generous bore, but spent boolit analysis back in my ballistics lab shows full engraving all along the length of the bullet.
The biggest pain was a set of brittle Fat 30's that went all the way through the rubber mulch and shattered against the steel plate. They had to be mined to get them separated from the mulch. (Most people would have left them, but I seem to have an obsessive thing going.) On the up side, they were used to win a practice high-power match - Argentine Mauser vs M-14's.
The 439186 was paper-patched and fired in a rolling block with a very fat .446" bore and they still show rifling.
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Originally Posted by TCFAN
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