Moonpie, I had the DCM NM barrel installed on my v-match so we're almost shooting the same thing.
First on all, my gun has been very ammo sensitive. UMC, Q3131, and my ball handloads shot poorly between 2 and 3 in. groups. (100yd benchrest with scope)
With the extruded powders (4895), and the Sierra 68gr, I'm down to 1.25in. I havn't got to try Varget yet.
Now, with the Sierra 52gr. and 784 I'm down to a consistent 0.8in. 10 shot group (usually with 7 or 8 shots in one hole at 0.5in.) But, I've found you have to let the barrel cool between shots with the 748 or it will string vertically. Seems very temp. sensitive and I will try another powder.
There you go, thats where I am at this point. Hope this helps.