I did lots of testing for my 7mm wsm last summer. Didn't get anything "Decent" until I started using the 162 gr Hornady interlok, (I suspect) because it was able to seat up to the lands, while the 139gr and 154 gr interbond were not. The magazine length on my ultimate shadow restricts the COL. I ended up with H1000 powder, but still not completely satisfied.
I get LOTS of fouling with this gun despite several treatments of JB, attempting to hone the barrel.
I'm going to do some ladder tests, once my chrony arrives.
If anyone else has tips on the 7mm wsm, please post them.