09-18-2020, 11:57 PM
Well I think I got this answered. Being fed up with the temp sensitivity of CFE 223 in my 6.5 Grendel load, I loaded up a ladder with 8208 XBR and kept everything else the same (Lapua brass,123 Scenar, GM205M). I had been getting 2600 fps with 30.4 grains of CFE (31.2 book max) at 95 degrees ambient (ammo stored at 80). Was 95 this morning, ammo had been stored at 80, and I started getting ejector marks at 27.2 grains (28.0 book max). XBR is quite a bit faster than CFE so I'm gonna guess slower powder helps timing. The 6.5G barrel is 22" JP with RLGS, JP LMOS carrier and tuned silent capture spring.