120 class powders

[LRRPF52]

My chamber doesn’t seem unusually short does it ?

ETA: Just saw your dummy cartridge COLs. Those are all within spec, right where they should be, and now you see the confirmation about 120gr ELD-M.

Make a dummy with a 123gr A-MAX, ELD-M, Scenar, or SMK and see what you can load.

120gr A-MAX and ELD-M have never been able to be loaded to mag length. Hornady actually had a factory 120gr A-MAX load that was quickly discontinued because of that, and why they developed the 123gr A-MAX.

ELD-M is an A-MAX with the new harder polymer tips. A-MAX used softer tips.

Precision Firearms cuts with a SAAMI reamer, which has the compound throat proven to exhibit better accuracy across a wide range of projectiles.

Most manufacturers use a non-SAAMI reamer with a parallel freebore for ease of mass-production and reamer life.

I’ve a bit of back-to-back testing using the same barrel profiles and manufacturers with the SAAMI vs parallel freebore, and the SAAMI chamber would shoot bug-holes while I could barely hold 1-1.5 MOA with certain loads in the parallel freebore chambers.

This was especially apparent when I pulled the barrel from the same rifle and replaced it with the same barrel from Lilja, only a Manson reamer-cut SAAMI chamber on the replacement pipe. These were heavy bull profile 22” fluted pipes from a heavy bullet rifle as well. With the SAAMI chamber, I was rapid-firing .3” to .6” 5-round groups at 100yds, with photos and witnessed.

With the SAAMI chamber, you should be able to load the 123gr A-MAX, ELD-M, SMK, or Scenar to 2.260” without jamming the lands. It will kiss a little bit for alignment, but not jam.