Well been going to the range alot to test loads for this rifle. Here are some good starting points for anyone that has a 7mm Gibbs. Some notes apparantley this barrel does not like boattails it will not shoot them and it does not like the Nosler/winchest combined technology bullets either. It shows the most potential with the flat base bullet especially with Speer flat base bullets. I tried some Hornady 175 and it shot them pretty good I got up to 56.0 grs of H-4831 with that bullet and stopped it was not showing any pressure with that load. So I feel I could of got up to an easy 58-59gr with that bullet. But stopped and started messing with 160gr bullets.
I just recently got a chrono so the only load I have chrono are these loads:
160gr Speer 61.5gr of H-4831 CCI 250 26 inch barrel. Velocity with a 5 shot string 3023 F.P.S was the avg. No signs of pressure.. I have tried H-4350, RL-22 and H-1000 but groups were not good at all. I have been tempted to get some IMR 7828 and some IMR 4831 to try out in it. But I guess for now I will stick with H-4831 it seems to be working pretty good.

quote:

I just recently got a chrono so the only load I have chrono are these loads:
160gr Speer 61.5gr of H-4831 CCI 250 26 inch barrel. Velocity with a 5 shot string 3023 F.P.S was the avg.

For info QL says your H4831 is a touch faster than norm and your pressure is around 64,000. Then using the same burn rate for the 175gr QL calls it 2755 @ 55125.

My 280PDK is a couple grs larger than the Gibbs. I had my best luck with MRP as to accuracy and velocity. I was lucky that most of my loads swapped to my second lott of RL22

QL list the highest velocity for the 7gibbs and a 160 speer with MRP followed by N560, magpro, 7828sc and RL22.