Thanks to all for the recommendations. I was kinda thinking along those lines, but have never had to tailor a rifle for the ammo. I guess I could back off the loads, but they shoot do damn good. Since I hope to have my muffler one of these days, I'll start with the agb.
Ironically, I've found it to be just the opposite if I want to shoot heavier bullets with maximum accuracy and as much velocity as possible from a gas gun. Gas gun system MUST be tuned or accuracy at distances is inconsistent, brass life suffers and reliability of function is questionable; I'm after as much of all three aforementioned traits as possible.
50 fps with Varget isn't going to make up for a bad wind call over the known load that was shooting well at 1100 yards with 4064. I get it, done same thing myself (bit more speed is more better) but reality is the 50 fps won't make up for a bad wind call. IF that 50 fps costs you reliable functioning of your gas gun, is it really worth the cost?
I'm a HUGE fan of Varget but will say that in 308 gas guns, 4064 is DANG hard to beat for the overall performance it offers.
Yes, you can make Varget work well for your 24" DPMS, that is a known and many, MANY people have done so.
If you have a higher back pressure can in NFA jail that you will be adding later to the DPMS 24"....the fun hasn't even started yet. You'll see appreciable difference between how rifle behaves with can on vs. can off.
If getting one can to run on bolt gun and gas gun, I can see the appeal of going with TBAC, Mack Bros, Rugged, Dead Air, Silencerco or other higher back pressure cans as those cans do better at suppressing on bolt guns. LaRue TranQuilo may not suppress as well at muzzle but bang for buck has been the best gas gun suppressor I've used in terms of how long rifle will run w/o needing additional lubrication, cleaning and number of rounds fired before starting to see failure to function and not requiring adjustment of gas system to function when can is on vs. can is off.
I've heard the OSS flow thru cans are right there also, I just don't have any first hand experience with the OSS products.