Ggg 308

[bullbarrel]

use 155 SMK's and 42-45grns of N140, remember to work your way up to the load and start low, GGG milsurp cases are probably lower voume than commercial brass so take it slow.

Totally agree about smks and powder. But I'd say invest in some new Lapua Brass. Its not a lot in the big scheme of things and you can reuse them many times if just neck sizing.

DONT use a mixure of cases. They will have different internal capacities and provide inconsistent results.

Once you've decided on the correct about of powder, if after ultimate accuracy then measure your guns maximum COL (several ways to do this) and make up batches 10 thou off going back to about 50 thou to see which one gives you the best accuracy.

Powder gives you FPS, COL gives you accuracy.

Happy reloading.

[Parabuteo]

Totally agree about smks and powder. But I'd say invest in some new Lapua Brass. Its not a lot in the big scheme of things and you can reuse them many times if just neck sizing.

DONT use a mixure of cases. They will have different internal capacities and provide inconsistent results.

Once you've decided on the correct about of powder, if after ultimate accuracy then measure your guns maximum COL (several ways to do this) and make up batches 10 thou off going back to about 50 thou to see which one gives you the best accuracy.

Powder gives you FPS, COL gives you accuracy.

Happy reloading.

Powder also adjusts the harmonics. A ladder test will show that powder also controls accuracy as the rifle hits a node. My old dolphin could be made to group well then diverge every .6 of a grain or so.

The ladder test will show single rounds with very small changes of charge forming groups as you hit the nodes. It is a very cheap and effective way of initial load dev.