[PSYCHO-FREEP]

Good points, military weapons design their chambers with longer throating to prevent potential accidents. Few civilians know this. Military ammo is also seated out further and few shooters know what their “sporter” is throated at.

I have seen “blowed up guns” at the range before, from guys using military ammo in their custom sporter.

[Gaffer]

If you’re talking 223 vs 5.56, you’re right. It’s called “leade” difference. If you look at SAAMI specs for both rounds you’ll find the dimension difference. The 5.56 also has a higher pressure on detonation.