P.O.Ackley noted that the Mark 5's he tested had at most, 3 lugs bearing. Seems to have been enough, though.

I never got used to and actually stopped shooting people's .300's at the range. I didn't like that whip-crack-snap of the ultra-fast recoil. I guess their stocks just didn't fit well enough. I did like shooting my .375 mag and .458's though.