"Any given cartridge will have a specific ammount of recoil with any given bullet weight regardless if it has a plastic tip, bonded core, partition or plane jane construction. A 150 grain bullet at 3100 fps is a 150 grain bullet at 3100 fps."

You couldn't be more wrong. I base my opinion on experience. I fired 10 rounds of 140 grain Winchester Accubonds and couldn't fire anymore because the kick was so bad. I next opened up a box of Federal cheapo Classic 150 grain soft points (ON THE SAME DAY AND AT THE SAME SITTING) and almost felt no recoil at all.

Therefore based on my experience, my conclusion is more based on type of slow burning or fast burning powder charge that is used rather then bullet weight. BTW, muzzle velocities were both 3150 fps according to the respective boxes.