Back in the early 70s, before any of the current .50 BMG rifles were born, I had a good shooting friend that worked in the armament lab here at Eglin AFB.
We'd frequently arrange to meet at the range and he'd bring along "interesting" weapons to shoot.
He decided that he wanted a .50 cal rifle. So he got ahold of a bolt action receiver of one of the Scandinavian countries' WW2 anti-tank rifles and had the engineers machine a Ma Deuce barrel to fit the receiver.
Worked pretty good, except that after firing a round or two, he decided that it needed a muzzle brake.
