What was behind the Kevlar vest in your penetration tests? What about trauma plates?
Well, that's a pretty important question, but I think we can cut to the chase and predict that 1) the zippy 5.7 rounds would penetrate not only Level II kevlar, but Level IIIA kevlar no matter what you put behind them, and 2) some trauma plates will defeat the 5.7mm rounds, but not all.
It's virtually axiomatic that light, fast bullets penetrate armor very well. What they do past the armor is what you really need to test.
I have not tested the 125's from Barnes in the 357 as yet.
But I have tested a lot of ammo and bullets and shot a lot of game and my statements stand on the 125 JHP VS a 158 I'll take the 158 every time. These are lead core bullets that I am talking about
I've "tested" 357 Mag Barnes 125 gr ammo on Level IIIA armor and in gelatin. (I use the word loosely; I didn't follow full protocol, so it hardly counts as a "test". It was more of a matter of satisfying my curiosity and I wouldn't say it has any validity worthy of publication.) It doesn't penetrate the armor. But it does perform very well indeed in 10% gelatin.
The old 125 gr SJHP load that "made" the 357 Mag's reputation as a manstopper was not a particularly good round, by current testing standards. It was a LOT better than the lead roundnose and SWC bullets previously in favor with law enforcement prior to the 125 SJHP's introduction and widespread use, though.
