Varget/RL15 will be WAY too compressed to get 5.56 velocities out of that rig, and as a Wylde chamber you'll likely be just fine shooting at them. I'm a varget/RL15 fan, to be sure, but they just don't have the oomph for higher speed out of a small round like 5.56.

I run 77 SMKs through several of my guns at 25.2 grains of AA2520, which is over max for their .223 data but not even close to max (and I don't see any pressure signs there) in their 5.56 section. Obviously work up to that.

Definitely get some 2520 though, it meters like a dream and gets fantastic speed without making turkey patterns.

I have 4 guns that run that combo MOA or better to 300 (furthest I've really gone with it), and the one rig I've chrono'd is a 16" Semi-Holland-Esque build that puts em a little under 2750. Flippin smokin.

(OPS collar and brake will replace the yankee hill doohickey soon as the applicable suppressor is out of NFA jail; for the meantime I'll keep the fugly YHM mount so i can shoot suppressed)

[Linked Image]