The snow-storm of particles from the M193 is predicatable; many 55grn and lower weight varmint bullets do this when they hit groundhogs or prarie dogs. Looks like you used a decent test media in place of gelatin.
The M855 broke right at the cannalure just as expected in gelatin. Did the steel core also break or is that thing complete ?
That would be me. I have never gotten the Prvi to do more than slightly flatten in phone-books at 100y with a 20" rifle (they werent very damp, but I don’t think that matters too much when it just comes to breaking the round in 1/2). The Q3131 looked just like it does in my original post, fired at the same distance into the same books one the same day from the same rifle. The Prvi was striaght, and slightly flattened near the base.
Also, it was fired at a distance of about 5’ into a 35gal trash-can and here are the results…I was unimpressed and it is now plinking ammo.