Not many men can stand up to a 4 bore with normal hunting charges - and then, are likely to develop a flinch that will never leave. This happened to Selous who used single barreled 4 bore Dutch smoothbore fowlers, cut shorter, for his elephant killing. Full charge, 16 drams - figure it out, 1 dram is a 16th of an ounce - 16 drams ia full ounce.

WW Greener broke his recoil machine with a 14 dram load, 382gr. The machine registered up to 200 pounds recoil and the lighter 14 dram load was enough over that, that the machine broke. A .458 WM comes back at about 56 pounds in a 9 1/2 pound gun, while a .460 WTBY is around 85 pounds, both with factory loads.

No wonder Selous developed a flinch.

Can't imagine shooting a 2 bore (1.35") rifle or smoothbore, even with a light 300gr. load. We have a reduced bore cannon, with a 1.5" bore. We shoot patched 1.4" WW balls with 300 to as much as 800gr. of powder from it. Even the 300gr. charge gets supersonic and rolls the 600 pound gun back on it's wheels. We put 6 or 7 into a 6" circle at 100 meters with it, winning the cannon shoot at helfey Creek Rondy last August. We're just getting to know the gun and are developing good loads for it.