18" 308 barrel velocity?

RidgeRebel

Sergeant
Full Member
Minuteman
Apr 18, 2009
266
1
Hurricane, UT
I don't have a chonograph so I was hoping sombody might be able to give me some average velocities for Fed GMM 168grn out of an 18" barrel. Or possibly give me an idea of how much velocity is lost going from say a 24" barrel to 18"? Thanks for your help.
 

xringdb

Sergeant
Full Member
Minuteman
Aug 11, 2007
265
1
Nashville, Tennessee
Re: 18" 308 barrel velocity?

Most testing I have seen say approximately 25 fps. per inch. With my reloads 155 gr. Bergers over Varget I get 2940 from a 24" barrel and 2805 from a 18" barrel, same make and twist. With a 165 gr. Nosler I get 2610 from the 18" barrel.
I haven't shot any FGMM but I would think 2600 fps would be close.
Hope this helps.