Beautiful custom rifle, huge fan of the Mauser action. I have been shooting, competing and instructing 50 BMG rifles for 20 years. I have a lot of trigger time on the M82A1, Tac 50 and the AR 50. They are all big heavy rifles with efficient muzzle brakes, those attributes are important when shooting the big 50. Don’t know how much that custom Mauser weighs, but with that length of barrel sans a good muzzle brake, it would be brutal to shoot. And it would clear a radius around that muzzle with it’s muzzle blast.
Having said that, it is still a beautiful example of craftsmanship.