Thanks for all the replies.  I have found, at least with the US Krag chassis, that there seems to be no steadfast rules on how to fit the stock.  I have a cut down rifle that someone converted many years ago to a carbine and I actually really like the shorter length.  It's a very comfortable and handy length.  I put a new Criterion barrel on that and played with screw pressure and barrel/stock pressure etc., but have found that it shoots best if it is pretty much locked down in the stock.  The one "trick" if you will that really seemed to help it out was to place a piece of brass shim stock on top of the forearm tip under the barrel and another piece of brass shim stock under the front barrel band exerting downward pressure on the barrel.  Don't ask for a scientific explanation, but those two pieces of shim stock took that carbine from shooting sporadic 3" groups with flyers at 100 yards to around 1.5" groups with nary a flyer.  Hard to believe, but that little Krag make believe carbine has become a favorite of mine even though it is not correct in almost any respect, but it's a gas to shoot and draws a lot of attention at the range. 

My Krag rifle remains a source of frustration.  I would have thought a new Criterion barrel and good install would have resulted in a very nice shooting rifle, but that hasn't happened yet. 

Rick H.