[RC one]

Yep. The thing about those AR15 pistols that I have noticed is that bullets tumble. I have one of the Bushmaster variety and my targets were full of keyholes. A tumbling SS109 is probably more lethal than a non-tumbling SS109, assuming he was using M855 ball ammo. If he was using M193 ball ammo with 55 gr projectiles, the bullet might still have had fragmentary effects at close range which make it particularly effective.

The Korean dude at Virgina tech killed 33 people with a Glock 19 9mm handgun so it's like I like to say, it's the Indian, not the arrow.

[JD_UTDallas]

If your short barrel keyholing the twist rate for the muzzle.velocity is too high probably a 1:9 or 1:14 you need at least a 1:7 to stabilise the long ss109s at the low.velocities of a 10” or under barrel.