According to load data 6.5 prc gets about 3000 fps give or take with ~60 gr of powder out of a 24” barrel. The 277 sig fury gets 3000 fps with 140 out of 16” barrel out of a 16” barrel using basically a 308 win case. Load data shows a max charge around 48 gr in a 308 case with 175gr (same sec density as 140 .270. According to jbm in 7 lbs rifle that is 22.3 ft-lbs of recoil for 6.5 prc and 18.9 ft-lbs for the 277 Fury. Of course if you use a longer barrel, 277 sig fury will likely be 3200 fps but that is not the point. In a 16” barrel the 6.5 prc would probably be 2800 fps and 20.6 ft-lbs so still more recoil unless the jbm calc is wrongThe weight of the powder charge is minimal addition to recoil. It is bullet weight, velocity and rifle weight that matters. You increase velocity by 15 to 25 percent, you increase recoil period. Most people despite all the talk just cannot handle recoil.
The formula for recoil velocity is \(V=-mvM\), where \(v\) is the bullet velocity and \(M\) is the mass of the gun. The negative sign indicates that the gun moves in the opposite direction of the bullet.
There is no free lunch. Push up velocity you push up recoil.
Lou