[smg]

Will the 7.62 x 39 mm FMJ 125 grain round when fired from a mini 30 penetrate a 1/4" thick low carbon (A36) steel plate at 50 yards? Will the .223 FMJ 55 grain round when fired from a mini 14 penetrate it?

 

[cajungeo]

The 7.62x39mm velocity would be 2142 fps, energy 1273 ft/lbs.
The .223 velocity is 2997 fps, energy 1097 ft/lbs. My money would be on the 7.62x39mm at 50 yds.

 

[mark webley]

yes and yes. they kill a plate in a hurry.

 

[bubba052698]

"The SS-109 can penetrate the 3.45mm standard NATO steel plate to 640 meters"

Here is a spec for 62 grain 5.56 NATO

 

[KING]

If you ever find any steel core 7.62x39 the penetration will be better than regular ball. The ATF bann further importation of the steel core when Olympic Arms made an AR15 type pistol in a 7.62x39 cal. I guess this constituted shooting AP in a Pistol configuration. I believe if the core is more than 25% steel, tungsten, berrillyum copper, etc. The ammo is considered AP. SS109 is NOT considered AP. The Penetrator button is very small. Good luck and good shooting.