I dont' know that this is actually proven scientifically. But there is also percieved recoil. I"ll take a stab at the 165 vs 230 issue. Both are available in the 45 ACP round. I carry and shoot both in my Kimber. The 230 should have more recoil because its heavier and in the same cartridge. But the recoil impulse is slower since the speed is slower. The 165 should be lighter in recoil but it runs a fair amount faster so you are smacked faster. I've found that often times sheer speed of impact of recoil can bother folks more than ft pounds do.

Thats my personal impression. I'd rather get shoved a lot and slower than not as much but at super speed. No I'm not saying 35 Whelen vs 22-250 though.

Final thoughts, the 165s in my Kimber are fairly sharp in recoil but don't move the sights off CM as much as something like a hardball 230 grain round does. In the end I think both rounds are about the same. And both are sharper than a 185 gn semi wadcutter target round thats both light and slow.

Jeff