[Martino1]

I’d give the powder company a call. They probably have an algorithm that takes into consideration case volume and bullet weigh to get you started.

 

[Martino1]

I have a Remington SPS Long Range in .300WM and the 1:10 twist barrel is just on the limit for 230 gr Berger Hybrids, I would think a 250 gr would need a 1:9 twist to stabilize.

I had a Remy 700P in 308 with a 1-12 twist and I was able to hit out to 1K yds with a 175SMK. I'm surmising that the 1-12 stabilized the pill enough to get me out to 1K. I suspect that 1-9 would be better but give it a shot with what you got.

Curious, did you call Hodgdon powder folks? if so what did they say. I've got a 300NM that would probably like a 250gr pill.

 

[Martino1]

Hysteria There seems to be a trend toward heavier for caliber bullets reaching out farther then their lighter counterparts. I'm a bit lazy so I try to find the bullet that reaches out the farthest and I stick with it so I don't have to mess with scope adjustments and different range card info. Pretty sure that there is a diminishing returns to a factor when it comes to bullet weight where the increase in bullet weight decreases the effective range of the caliber in question. Don't know where that is for the 300WM but I have read here were guys were getting good results with 200gr Sierras in 308's. I suspect your 300wm should be able to go heaver since you're moving the same bullet about 300FPS faster if you're shooting a 150gr as a baseline comparing apples to apples. Just a thought.. I'm curious what a 250 would do in a 300WM..

 

[Martino1]

I asked Hornady via email & they stated that the 250GR A-tip requires as 1:8.5" twist. They stated that my RPR 300WM with a 1:9 twist was not suitable for the projectile. They still haven't got back to me on the power type/charge amount

My 1:12 twist in my Rem 700P in 308 was not ideal according to the many of the twist charts put out by the barrel manufacturers. Still I was able to hit 18x24 targets at 1000 with a handloaded 175SMKs with reasonable regularity. I did not have any joy trying to ding a 4" diamond at 1000. That was a little aggravating. I had the action re-barreled with a 6.5CM Bartline barrel when the groups started opening up. I got handloads doing bug holes at 100 and before I could get out there with my bug hole load, the range closed for public access. I'll have to find another 1K or longer range. Once I got dialed in at 1K prone, shooting less distance for me was not a challenge unless your talking PRS style shoots. Those can be tough even at closer distances due to the time pressure and multiple positions firing positions added.