450Bushmaster.net

Thanks guys for the help. Tex what grain increment would you suggest for the ladder pressure test. They say 1% of charge weight, but could i go a 1/2 grain increments??

1/2 grain increments are fine. I bump up a 1/2 grain in all my work ups for the 450B. Only if loads have used by quite a few people here will I move up in 1 grain increments. That's me though.
Also on another note I know Tex has done extensive work with 230gr pistol bullets, this bullet is not the same. So just work up slow and keep track of your case measurements.

Ok half grain it is. I absolutely will. Ill post my results after the range visit this weekend.

shooter75 wrote:Thanks guys for the help. Tex what grain increment would you suggest for the ladder pressure test. They say 1% of charge weight, but could i go a 1/2 grain increments??

For Thumper I usually go in 1/2, (0.5), grain increments. But when I was working up my 230 Grain FMJs, I was more cautious because I knew I was headed into the twilight zone trying to punch a hole in 7/16” steel plates. I think some of my unpublished loads, I was going up in 0.1 grain increments once I passed the 2400FPS threshold. It proved to be a crazy amount of work and it was probably not really a good indicator. Five rounds each at 0.5 increments where much less work.
Not to mention less expensive. I ate up all of my Hornady 230 Grain flat points and I’m still kicking myself today for that.

Sooo. Just got from the range and have some results from my ladder test.

RAR 450 BM 16.1" barrel
Lil Gun
Rem 9 1/2 primers
Onced fired cases
2.236" COAL
220grn Lehigh Xtreme Hunter Bullets

Grains - FPS

38.0 - 2,512
38.5 - 2,414
39.0 - 2,549
39.5 - 2,573
40.0 - 2,592
40.5 - 2,520
41.0 - 2,526 - Primer Cratering / Stopped Ladder Test

Factory Underwood Ammo - 220 Grain Xtreme Hunter

Round - FPS

1- 2,294
2 - 2,288
3 - 2,287
4 - 2,291
5 - 2,318
6 - 2,322

Factory stuff pretty consistent.

I'd be pretty happy with 2500fps thou.

How was accuracy?

Yeah i was impressed on the factory consistency but it grouped like crap at 50 yards. Not to impressed. The top hole was a cold bore shot.




As far as the reloads ill be sticking in the 2500 fps range for sure.