The rule of 96 works pretty well for me, so long as velocities are 1150 to 1200 fps. But most of my factory ammo for field use runs 1300 fps. Some quick retrospective figuring tells me that a rule of 104 to 112 works better with B&Ps - their claims of recoil mitigation, notwithstanding.

I don't worry too much about gun weight - my field guns run between just over 5# 3oz to 6# 15oz. MOI will influence my field performance alot more than will gun weight.

Sam