How much velocity can one expect to Loose or Gain in barrel length per Inch for Big Bore caliber such as .458 Lott and/or 416 Rigby?

Thanks
Steve

I shot the same loads in my 416 rem mags.I had a 22" barrel Remington model 700 and a Winchester model 70 24" barrel.There was only about 75 fps at most difference in the two with bullets from 350 gr to 410 gr.The biggest difference was in the 325 gr there was a 125 fps difference.They were more accuate in the longer barrel also.It was not as much gain as I thought it would be.

Some here report 25fps/inch and others 50fps/inch. Probably depends on your rifle and load.

465H&H

You don't see as much drop off w/ big bores & big bullets as smaller bores. Like DGR, you'll see little diff. mayve 25fps for heavy bullets & as much as 50fps/inch for lighter bullets. I think at most ranges you would use a heavy for (200yds max.), it just doesn't matter.

Most sources say 25-40 fps. If you are talking about a 2-3 inch difference the game will never know the difference. Good hunting. D

In barrels of identical length you could easily have differences of over 100fps. Your Remington could have a fast barrels and the Winchester could be slower. But 75 fps for two inches of barrel length is not bad for a big bore.

Go to the Remington Ammunition site. They had a page devoted to this subject. If memory serves it is based on a standard length of 24" and is bore dependent and is in velocity ranges. It is absolutely insignificient in most big bores. Like 10fps per inch for a 416Rigby.. That's from memory but not far off. Both my CZ 550 416Rigby and Brno ZKK 602 375 are cut to 21" based on this data. I have the page printed out somewhere, I'll look for it and print if I find it.

I cut 2 1/2" off my first .416 Rem. (24 1/2-22")and lost 50fps with my hunting load.