30-378 Weatherby Velocity

[CENTURY]

What should I expect for velocity increase going from a 26" barrel to a 30" using 181 gr Hammer Hunter bullets.
My 26" gets 3450 fps with a 1 in 12 twist but will not stabilize them. The new 30" barrel is a 1 in 10 twist. I will be using Reloder 26.
Any loads or starting points using Reloder 26 would be greatly appreciated.

 

[FEENIX]

What should I expect for velocity increase going from a 26" barrel to a 30" using 181 gr Hammer Hunter bullets.
My 26" gets 3450 fps with a 1 in 12 twist but will not stabilize them. The new 30" barrel is a 1 in 10 twist. I will be using Reloder 26.
Any loads or starting points using Reloder 26 would be greatly appreciated.

~75-100 FPS +/-

Steve might have a load for you.

 

[Muddyboots]

You should talk to Steve on the 181 versus the new 180. The 180 was a redesign for better stability in 1:10 twists. Just a heads up to consider. Plus they are on sale!!

 

[budlight]

This is just my opinion because my 30-378 was do for it's third barrel when I sold it. Yes I used 30 inch and 2 inch brakes 10:1. Yes it was a 1000 yard comp gun. You get @ 500 rounds or less before the barrel was toast even using the slowest powders. So with that in mind you don't have lots of time for load development or chasing some FPS bragging rights. Who cares if you get 3700 fps if it splatters all over the paper.

so what is it used for? mine was a paper and elk rifle. so I put my effort into Berger 210 VLD hunting and 220 vld target bullets. dabbled in 240's

Retumbo and US869 were my only powders. Rl 33 and 50 wasn't out then.

Quick load can tell you the expected speed, but adding 4 inches might get you another 100 fps. I also home moly coated my bullets to get a little more barrel life

 

[CENTURY]

Thank you for responses, I have had great success with the 152 gr Hammer Hunters on many elk, have also used the 210 LRAB on elk with success, I wanted something in the middle to utilize speed as well as more weight than the 152's. I already have the 181 gr Hammer Hunters but if for some reason they will not stabilize in the 1 in 10 twist I will go with the 180 gr Hammers.

 

[Muddyboots]

Century, I bet Steve would trade you the 181 for 180 which he has done in past if that was a concern. Really good to work with on these types of issues.

 

[CENTURY]

Yes I believe he would, when the 181's would not stabilize in my 1 in 12 barrel I spoke with Steve and he sent me the 152's at no charge which worked great.
Steve is a real class act with great customer service. Hoping the 181's will stabilize with the BC of .272 compared to .243 of the 180's.

 

[cape cove]

With the load I use in mine QL shows a 150 ft/sec difference between a 26" barrel and a 30' one.