The following examples of recoil energy and velocity are all measured in 8 pound rifles. (Caliber [bullet weight, muzzle velocity] = free recoil energy & free recoil velocity.)
[ul][*]6mm Rem. (100 grain, MV 3100 fps) = 10.0 ft. lbs. & 9.0 fps[*].270 Win. (140 grain, MV 3000 fps) = 17.1 ft. lbs. & 11.7 fps[*].30-06 (180 grain, MV 2700 fps) = 20.3 ft. lbs. & 12.8 fps[*].35 Whelen (250 grain, MV 2400 fps) = 26.1 ft. lbs. & 14.5 fps[*].450 Marlin (350 grain, MV 2100 fps) = 35.7 ft. lbs. & 17.0 fps[*].458 Win. Mag. (500 grain, MV 2050 fps) = 68.9 ft. lbs. & 23.5 fps [/ul]
In the typical examples above, as the bullet weight goes up the muzzle velocity (MV) goes down; but the recoil energy and recoil velocity both continue to go up. The heavy bullets at relatively low velocity do not deliver a "long slow push," they deliver a progressively harder and faster blow to the shooter. Note that the high velocity .270 with its 140 grain bullet has a recoil velocity of only 11.7 fps, while the relatively low velocity .450 Marlin with its 350 grain bullet at 2100 fps has a recoil velocity of 17 fps!
Rifle weight plays an important role in determining the amount of recoil delivered to the shooter's shoulder. For any given caliber and load, a lighter rifle kicks more than a heavier rifle. Which is why I avoid ultra-light hunting rifles. Here are a couple of examples showing the effect rifle weight has on recoil energy and velocity when shooting the exact same load.
[ul][*].300 WSM (180 grain, MV 2950 fps), 6.5 lb. rifle = 30.8 ft. lbs. / 17.5 fps[*].300 WSM (180 grain, MV 2950 fps), 8.5 lb. rifle = 23.6 ft. lbs. / 13.4 fps [/ul]
[ul][*].45-70 (300 grain, MV 1900 fps), 7.0 lb. rifle = 26.6 ft. lbs. / 15.6 fps[*].45-70 (300 grain, MV 1900 fps), 8.5 lb. rifle = 21.9 ft. lbs. / 12.9 fps [/ul]