I've been shooting a 444ss(22" barrel) for years with nothing but the brick of a pad Marlin used to put on them. No vents, nuthin'. I load it pretty hot and never shoot anything lighter than 270gr bullets. It will send you home a bit sore after a range session, but it ain't that bad IMO. With a better pad, like a Decelerator, it would be much better. My friend shoots a 450 Marlin with the short(18.5') ported barrel. I absolutely hate it. Yeah, the ports reduce recoil, but the muzzle blast is deafening. I'd rather more recoil and no porting.....
