Im waiting on the AR500 results. My swinging 550 gong dimpled at 75 yds with a 40 grain vmax out of a 24" .223
That bullet is way too fast for armor steel, that close. 3200 fps MV is rule of thumb. High energy does not hurt them, high speed does.
When I've had clients want to get DOPE on .224" cartridges, I put clays on the berm at 200 yards, otherwise it'll dimple my AR 500.
Pretty sure this about sums it up thus far. We had complete penetraton on the 1/4" at a mv of 3150, but nothing really but a very light mark with the 77g smk at 2990fps.
This was part of the reason of the test.
There are several parts that intend to test other than that though.
Also, to answer another poster. There is some mathematical formula that gives a percentage of energy lost per degree of angle. I don't want to leave anything to guessing which is why I am shooting it square.
The jacket separation was due to full penetraton of the 3/8" mild steel and the thicker jacket construction of the target style bullet. It basically peeled the jacket from.the core, flipped it inside and created a lightweight, high velocity projectile in reverse.
Had that jacket been another inch to the right, it would have gone right back down the bore.
I also have no doubt that if that jacket would have struck the 3/4" plywood it would have stopped it.
Regardless, the testing will be completed, albeit with largely different testing protocols in place so we don't repeat the previous.
Ultimately, besides everyone seeing the fallacy of it, in the end I believe there will be some questions answered as far as external ballistics vs steel of a given composition.