I've got a stock that uses a barrel block type device, around the shop for this - I'll take a picture tonight ( I'm at my REAL job today ) and post it. It is heavy, slides in a bag type setup, and other than being UGLY, works pretty good. I want to say it is/was made by Goodson, but I'll get the info tonight.
300 sniper - your right, leaves out part of the equation, sometimes a good thing. It's one way to track down an issue - is it the barrel, the bedding or the trigger monkey?
Having recently taken up BR shooting though, proper trigger pull and follow thru is STILL important with a 4 oz trigger, you wouldn't think so, but have found it to be so.