C.O.L Question

[canadianshooter]

I'm working up a load for my .308 rifles. The intent is to make a low cost .308 plinking round. I'm using PRVI 150gr soft points. I tried 748 with huge groups. Then tried Varget which has reduced my groups to just over two inches (not exactly great). I'd like to keep within SAAMI specs to allow using the ammo in several rifles. I've noticed the tested seating length in the Speer manual is 2.700" for flat base 150gr soft point. PRVI 150gr ammo is loaded to about 2.710. However the max case OAL listed in the Speer manual is 2.810". Why is there such a large difference between max C.O.L. and the tested length? Is the 2.810 COL still within SAAMI spec for all the bullets in the .308 section? Thanks.

 

[Ganderite]

I have loaded 308 for several hundred different 308 rifles.

if you want to make ammo that will fit many rifles, the COL issue relates to bullets hitting rifling and loaded rounds fitting magazines.

In my experience 2.815" is about max if you want to fit all the mags.

As for staying off the rifling, 2.800" seems to work. But my expeerience has been with spitzer bullets. A round nose might have to be seated deeper.