240 weatherby and 100 gran bullets

[maddysdad]

given bullets in this range and a 28 inch barrel what would you estamate the velocity gain over the standard 24 in barrels .

 

[Gary in MD]

Mostly guess work, but I’d say somewhere between 100-200 fps, possibly more.
Only way to say for sure is set one up at 28” and then get out the hacksaw.

 

[Bob3700]

given bullets in this range and a 28 inch barrel what would you estamate the velocity gain over the standard 24 in barrels .

I have seen some older charts for high speed cartridges and they showed 30-40 FPS per inch of bbl. for a 22/250.

 

[maddysdad]

thanks....was looking at a rifle that is a 30 06 necked down to 6mm with a 1 in 8 twist 30 inch long hart barrel.with the 107 sierria hpbt he is getting aroung 3450 to3500 fps.i was hoping to get close to this with a factory case .this is why the 240 weatherby is the look at.

 

[6MMWASP]

Berger reloading manual has Velocity changes per inch longer or shorter. Certainly not cast in stone but a pretty good estimate.

 

[Murray Brook]

Checked a load with QuickLoad. Used 53 grs of H-4831 with the 100 gr Sierra.
24" barrel----3218 ft/sec
28" barrel ----3351 ft/sec
Pressure for both loads according to QL --57770 psi
Just to give you an idea.

 

[Frankm]

125-150 fps … 240 is quite overbore so it ll like the longer barrel. My 24” shoots 100 gr bullet 3300-3350 fps depending on how I push it.

I d see a 28” barrel tickling 3500 fps!

 

[Frankm]

FYI, I shoot R26 which gave me close to 100 fps more velocity than 4831 varieties.