Originally Posted by ctrmass
I havent read all 5 pages, but AA 2520 is a pretty good powder for the 77's.
Accurates site has them going 2900 + FPS out of a 24" bbl.
bullet start FPS max FPS psi OAL
"2520 77 SIE HPBT 23.0 2,674 25.5 2,925 62,200 2.260"
This a "nato pressure" load. It dont say but I'd assume a 5.56 chamber.
From their site.
I'm not sure what you'd lose with a tube 4-6" shorter, but it cant be much.
For the 77-grain bullets, max load (i.e. fastest) is often not the most accurate. The load listed above is a max load ONLY to be used in 5.56, Wylde, Noveske or other higher-pressure chambers, NOT to be used in a .223 chamber.
Even with a higher-pressure chamber, start lower and WORK up to a given load--never take a max published load and assume it is safe for YOUR barrel.