It's essentially a 444 Marlin necked down to .411. You can use 41 Mag jacketed bullets, at pretty high velocity, or use it with heavy cast bullets. A 265 to 300 grain cast bullet would make it a pretty good stomper. Some are claiming 2000 fps with bullets of those weights. A 280 grain .411 at 1600 fps would do some pretty heavy lifting. There is some data on the Cast Boolits site.
I've been keeping an eye out for a rusty bore 336 in 30-30 or 32 Special for just such a project.
