I had a .50 Beowulf, actually a 12.7x42 so they didn't have to pay to use the copyrighted name. It was very accurate out to 100 yards. I installed a retro one-piece AR stock with the storage door built into the shoulder pad. Put in a weight from Brownells, made to sort of fit in the compartment, and it was a really fun shooter. A cannon-style brake helped too. I gave it to my younger son to pass on to his son who really enjoyed shooting the thing.
I thnk I insyalled a 7 or 8 power scope.
Starline makes brass, it is expensive to feed factory ammo.