.338 velocity for different barrel length

[midwesthunter]

What would difference be for say 338 RUM or edge in a 27" barrel with brake vs 30" with brake? Shooting 300 grain pills of coarse.

 

[4xforfun]

Three inches.

 

[jcoop]

Acording to this testing it should be somewhere around 50-60 fps.
Lilja Precision Rifle Barrels - Articles: Barrel Lenghts and Velocities in the 338/378 Weatherby Magnum

 

[D.ID]

It is really hard to say as not all barrels are equal but I would not expect even 40fps in a truly equal barrel. I shoot a very mild 89.0 grain load of h1000 with 300grn in my edge with a 24" savage factory barrel and it nets a verified 2781fps. I can run 2850fps if I load it up to 92 grains. Between those longer lengths in that bore size, The difference will be very little.