.408 Info

[qm1eod]

Hello All;
I am looking for a solid load with temperature stable powder for my .408.
I am currently using RL 25 @ 127.5 gr. I am constantly achieving 1 MOA groups @ 200 so all good but constancy at different temperatures for comp. shoots is a concern. I am considering RL 26 but not sure where to start. The data states that 26 burns slower than 25 with better velocities (Current Velocities are 2960 to 2966 fps) Help??
Thanks all

 

[THEIS]

Hello QM1,

How is the Navy treating you ?

Back to your question...
You are pretty much maxed out on MV without beating the **** out of your brass. You are actually only a few fps different than the "original" 408CT MV..before it was slowed down to 2850fps due to brass/primer issues. What is your MV deviation over a 10 round string?

What atmospheric/environmental conditions are you in when obtaining your current MV and its' 10 round string deviation?

What projectiles are you using when obtaining your current MV and its' 10 round string deviation?

I always used RL25 back during 408CT days but my load was 126.4 with the original LRBT projectiles.

THEIS

 

[Bravo 4]

I'm using 147.5 grains of RL33, 415 grain Cutting Edge MTH, Fed215M, Bertram brass, velocity of 2900 FPS. I pushed up to 3080 FPS before I got any pressure with this powder, which was over 100 fps more than RL25 got before pressure signs.

 

[qm1eod]

Thanks All,
After some trial and error I found that Retumbo @135.5 grain is producing a 4 shot group with 3 rounds in same hole and 1 slightly off center at 150 yarsds!! And 7.33" @ 1 click. (Bench of Course) my MV is around 2970 with a 5.2 SD with a 400 grain Lehigh solid brass projectile. I am not usually a fan of Retumbo however this Bartlin bore appears to love it. Also it is a Temp. Stable burner, I will continue to explore a bit, but I believe I have found a solid base to build on..
Thanks all, this has been a difficult run to find any info for this bore so if anyone else needs info feel free to message me. I may be able to help a bit and I may also continue to learn more as well.

 

[dfanonymous]

I remember the last time I owed beer...