Frank;
I too have an accurate DPMS LR 308B. It has had nothing but my reloads for
the 7 years I have owned it. I hope that yours is as great a rifle as mine is.
I use Federal brass, any large rifle primer, 41 grains of IMR 4895 propellant,
(this is just below Sierra's max charge with Fed brass.)
Sierra 168 grain HPBT match bullets. Chronos at an average of 2460 fps from the 18" barrel. Consistent sub moa accuracy.
I use Frankford Arsenal spray case lube, re-size to to a datum line .002" less than as fired, TTL @<2.008". I also deburr the flash holes.
IMR 4895 will suit your 16" barrel far better than the ssssllllloooooowwww
propellant you are using. If you choose to use other brands of brass, all of which have higher capacity than Federal, you may need to increase the propellant charge a few tenths of a grain. I tumble clean all cases before re-sizing / de-capping then tumble again to remove the sizing lubricant & help clean the primer pockets.
Bullets are seated to barely less than magazine length.
YMMV & good luck.
Roger