While I'm not of the crowd that touts long cones reduces recoil, I do believe there is more to how a person percieves recoil than the simplistic calculation using velocity, mass and gun weight. That calculation doesn't consider the nuances of time/acceleration of the mass within the barrel. Most of you here agree that the gun begins to recoil at least as soon as the load mass begins to move. I think many of you agree that different burn rates of powder will accomplish the same velocity with different peak pressure. I will go a bit further out on a limb and say many of you recognize that it takes the same total energy (a.k.a. "energy under the curve") to push a load to the same velocity no matter the time/distance to accelerate it.
So, if two loads of the very same velocity and weight of shot, using different powders, that have different peak pressures, the total energy expended has to be the same after all is done. That means the powder is exerting higher pressure further down the barrel on the lower peak pressure load. Some of us may not be able to feel that difference, some may. It's simply the inverse of how a hydrocoil "lowers" recoil. It spreads it over a longer time.
