This is the very first time that I hear about some "pressure pulse" problem associated with rifle grenades. I have some physics skills, but I can only imagine a tiny effect after the time when the bullet reaches the muzzle. The grenade might act as a cloture (hardly with bullet-thru, though) for a very, very short moment.

I doubt that this has any measurable effect, since barrels have a decent safety margin anyway.


About the buttplate damage; again entirely new to me. Soldiers do a lot with their rifles and rifles have to be tough anyway. The recoil of a rifle - even with a heavy projectile - should be well within the limits of normal harsh treatment.