I’m loading up for a 308 bore x39 (specifically the AR stoner). I’m getting great accuracy with a 308 Nos Ballistic tip in 125 grain, a hair shorter than 2.20 COL and 25.6 grains 1680. Velocity averages about 2385 with an extreme low of 2360 and an extreme high of 2408.
Max book loads for x39 with .311 123\125gr bullets show 2475 and 2496 with 1680 out of a 21” bbl. Based on research I should be losing something like 75-100fps with the shorter 16” barrel (if not less).
So the crux of my question—based on the information above, I’m assuming I should be well within pressure parameters with my chosen load, but wanted to verify with those having more experience. The 308 projectiles tend to be quite a bit longer than the .311, so it takes some work to develop a load, and I want to ensure it’s safe.
Max book loads for x39 with .311 123\125gr bullets show 2475 and 2496 with 1680 out of a 21” bbl. Based on research I should be losing something like 75-100fps with the shorter 16” barrel (if not less).
So the crux of my question—based on the information above, I’m assuming I should be well within pressure parameters with my chosen load, but wanted to verify with those having more experience. The 308 projectiles tend to be quite a bit longer than the .311, so it takes some work to develop a load, and I want to ensure it’s safe.
