Thanx to all for the great advice.
Scharfschuetzer, I am using XM193 ball ammo brass that was new when I purchased it. I will start weighing and culling as you suggested. the deswaging was a PITA and I actually flattened about 1 in 10 primers before I figured it out. I am using CCI 400 primers but I note some say they are to soft to use in a semi-auto.
The Savage and bushmaster both have a 1:9 twist. I haven't tried the heavier (69 gr) bullets yet but have ordered some to try.
When working up OCW on 40 gr NBT's this savage achieved 5/16th MOA at 100 yds. 22.2 gr H4198 powder. Will try 200 yds to see how stable it is.
Are you able to get decent accuracy with the 5.56 brass?
m&p45acp10+1, I am deswaging, reaming the pockets and I am glad that only has to be once.
I tried some federal brass I had saved and the primers holes were horrible to work with. Much worse than the military. So, I tried hornady brass and I agree it is much better.
Interesting that your 1:9 does well with 77 gr HPBT.