FPS gain in a 26 inch barrel vs 22 inch barrel

[coyote trapper1928]

How much FPS gain in velocity would you get using a 26 inch barrel verses  using a 22 inch barrel  in the 45-70 ?

[quickdtoo]

Depends on the load. I shoot the 300gr Nosler partition/H4198 at 2425fps in a  22" .45-70 barrel, the same load in a 32" barrel only makes 2450fps.

The 350gr Hornady RN at 2027fps with H322 in the 32" barrel, and 1850fps in the 22" barrel.

Another comparison is IMR4198 and the 350gr Speer FP, 1932fps for the 22" and 2082fps for the 32".

Tim

[jro45]

I had a 26" barrel put on my 7mm it had a 24" barrel and the increase was about 40 fps per inch. The powder I use is H4831. I use one load for the bullet that did this.

I don't have a 45-70 so I don't know if this helps or not.

[nomosendero]

I had a 26" barrel put on my 7mm it had a 24" barrel and the increase was about 40 fps per inch. The powder I use is H4831. I use one load for the bullet that did this.

I don't have a 45-70 so I don't know if this helps or not.

No, apples vs oranges in that one. The 45-70 has a fast expansion ratio, so adding additional barrel length does not help it the same way it helps a 7 mag., which has to burn alot of powder in a much
smaller bore, therefore a slow expansion ratio. You have Tim's examples & in some loads the difference may be a little more, but not much more.