It is not merely the weight of the bullet but the relative power of the load that has the most effect on felt recoil. There is a rather complicated formula but you can come fairly close by using the IPSC/IDPA "Power Factor" which is Bullet Weight X Velocity divided by 1000. i.e. a 124 @ 1100 = a PF of 136.4 while a 135 @ 1000 would be 135.Originally posted by Skunkabilly:
How does the grain number affect the recoil on a given round?
For example, 124 vs 147 for my 9mm, and 165 vs 180 for my .40. I hope these numbers are right.