24" 338 RUM velocities? advice needed

[chuck plissken]

I'm curious for info on real world feedback on your loads velocities with 24" barrels. I'm only thinking of 24" barrel length for 2 reasons. Easily fits in my hard cases I already have and its easier to maneuver v.s. a 27"+ barrel I originally wanted.

This will be a pack rifle used often in the field. Not a bench rest queen.

I will be using 250 and 300 grain projectiles. Barrel is 1-10 twist.

I'm hoping for an honest 2900 with 250gr and 2650 with 300gr.
What do ya think? I guess I don't need advice but maybe is it worth going 24" will the ultra mag?

 

[AZShooter]

I can't tell you what you will get with your 338 RUM. Can mention my experience though. I built a 24" 300 RUM for the 230 gr hybrid and am using RL-33. Most accurate load is 100 gr with the 230 going 2975 fps. I think you will do even better with the larger bore.

If you read Kirby Allen's thread where he used RL-33 he got his best results with lowest ES using heavy bullets into the rifling. I would bet money your 338 RUM will surprise you with the 300 gr bullet.

Alliant has load data for both weight bullets you want to shoot and with a 24" barrel!

300 gr sierra OAL 3.59" 99.3 gr for 2718 FPS.
250 gr sierra OAL 3.59" 106 gr for 2988 FPS

 

[aramarine6]

I have a 338 RUM with a 26 inch barrel. I would say that your expectations of velocity are on par for a 24" I get 2950fps with a 285 grain projectile. I'd imagine you could squeeze 2700+ with a 300 grain bullet.

 

[chuck plissken]

Yea I hope so. I'm just unsure which powder for a 24" would be best. Reloader 22 or H1000 are what I have. Retumbo might be too slow?

 

[aramarine6]

Both are good powders. I'd lean towards the H1000. I get great accuracy with it towards the max powder charges. However if you're going to be shooting at game at distance I'd pick the powder that gives the best all around consistency. Max velocity wont mean squat if you don't hit vitals.

 

[chuck plissken]

I agree. I prefer 1 moa or less. With hand loads a muzzle break and being a heavier contour I believe I can muster sub moa out past 600.

I would rather have a super accurate rifle andild loads v.s hyper velocities/energy and decent groups.

 

[angus-5024]

If you want to run a 24" barrel I would suggest a loot at the .338 Norma. It is right on par with the RUM but a little more efficient with short barrels.

 

[Kiwi Greg]

Retumbo will give more speed than H1000.

RL33 will give the best velocity.