Yeah, I just re-ran my numbers and realized I screwed up the first time. The recoil on the 7 mag 168 is a bit higher than I thought, I put in the wrong number for powder grains. Still, it's pretty close to the 308. But I think I have a handle on it now., and found the 150 LRAB in a 7mm is pretty great..
Here is what the recoil weight, speed, and then 1k 10mph drift numbers look like for various combos, all assuming a 10lb rifle, except for the 300, which assumes an 8.5 lb rifle. The numbers for the 7 mag are based on minimum book loads, mainly from Nosler:
7 mag 150 accubond
13.2
9.24
Drift 63.03
7 mag 168
15
9.8
Drift 63.50
308 168 berger
13.5
9.3
Drift 77.13
308 185 Berger
15.5
10
Drift 76.2
6.5 140 berger
11.2
8.5
Drift 62.23
3006 200 berger
19.97
11.3
Drift 66.44
300 Win mag 185 Berger
29.1
14.8
Drift 61.51
I tried to pick loads that got as close as possible for drift. The only ones that would do that on a 308 were 200 bergers (although I don't have the info for Amax's, SMK's or others, so maybe there are options there). The problem is, Berger says they won't work in a 12 twist. I'm going to see if there are some high bc 200 grainers that might change the picture, that will work in a 12 twist.
Stupid weatherby.....shoulda put a 10 twist!
Anyway, you'll note that 7mm 150 LRAB load is looking pretty good, second only to the....yeah...260/6.5...essentially identical in recoil to the 168 308.