before the 50 cals became popular, someone made a Breach feed single shot shoulder fired 50. The muzzle break was similar to the ones on the russian tanks. iirc, it was all SS tubing and was about as long as the rifle in the vid. The shooers said it was like shooting a 12 ga magnum. they were even able to hold the gun over their heads and fire it to proove the recoil was managable.
when i saw that, i realized managable recoil came down to how affective the muzzle break was designed.
