If its just factory velocity you want to match, don't bother worrying about it. Factory velocity ratings are based on on of their test rifles- comparing this to what it will do in your rifle is like comparing apples to oranges. Reloading manuals- pretty much the same deal, you can't accurately predict velocities unless you already have data for your personal rifle.

This is also the reason why you want to work up a load- in some rifles you load a little hotter than the maximum load, in others somewhat less to get to the point of high pressure signs.


If you just load for velocity- especially blindly without a good chonograph, you are ignoring the biggest virtue of the cartridge, which is accuracy. A .308 that shoots cloverleafs is alot more fun and useful than a .308 that shoots 100 fps faster and shoots 1.5" groups.