Traded for this one today. Custom 404 built on a Mauser type base uses 375 H&H brass necked up to 404, yes necked up. Haven't shot it yet so no report on a broken shoulder to make. This is one of seven made by a guy here in Oregon. This is gonna be fun to play with loads to see what it can do. The ammo pictured is l to r .45acp/357/338/ 404 with jacketed bullet it uses. This should make a rather large boom.