I can't say for sure, Mike. I do know I can fire many more rounds from my 500 without getting the 'car wreck' headache when I use the shield. I'm a skinny dude and I think the shield helps dissipate the shock to the anatomical system.

I don't usually bruise much even without the shield. I think what helps me the most is the shield padding acts like the flesh most normal people have on their bones!

Sometimes during bench sessions I find myself tensing my neck and shoulders in preperation for the recoil. The shield certainly minimises this tendency.

A 550 mag

That ought to stop a 'roo, eh?!!