Wow! Talk about perfect timing (the post or me reading it??). Couple weeks ago fired my Colt HBar Competition (20" bbl, 1-9 twist, Simmons A-Tec 3.8-12) from a front rest, shoulder held in the rear. Tried with an assortment of ammo, mostly got groups in the 1-1/4" range. Wierd thing was they all grouped pretty much in same place, so when I centered the clusters, they were pretty consistent for all ammo types.
Trigger was factory (lousy and went "sproing" on release!) at 8+ lbs; installed a Jard 3 lb tonite ($135 with hammer from Brownells); haven't shot it yet.
Was expecting tighter groups, but guess it's pretty good as it is... Just read about an Olympic Arms in "Gun Tests" that got around 3.4" and they thought that was pretty good!!
As long as it's "Minute of Groundhog @ 100', guess I'll leave the bbl alone!
Arden