FWIW- this information pertains to a fireforming load in a 223AI chamber. The barrel is 26" long and features a 7-twist.
73 ELD-M over 22.5 of 8208 XBR lit by a CCI 450 (Fiocchi brass) got me 2850-ish FPS with the projectile seated ~.010 into the lands. Accuracy was difficult to determine because I was also breaking in a brand-new barrel, so I was stopping, cleaning, etc..., which means that the barrel was getting warm, cooling off, clean, moderately dirty, etc...
I have a couple of those and are stubby enough to work in my 1:8 at my elevation. I'll have to try that load.
Otherwise I have had success with
1:8 24" bolt gun
77SMK and 77 Nolser Custom Competition
26gr of Varget (crunching powder kernels)
2.290" OAL (at the lands in a Manson SAAMI .223Rem reamer)
Runs close to 3000fps and .5 MOA at 200yds.