The laws of Physics are irrefutable, light guns kick more, good grips help, but don't EVER think practicing with light loads will prepare you for Magnum recoil. Practice with good ammo, with 38+P as the minimum, I personally think a barrel under three inches can't make magnum ammo anything better than a 38 flame thrower, that will blind both you AND the bad guy. Up close, where most of the feces hit the fan, I'll take something that expands over something that overpenetrates every time. Just mine dos pesos.
Papajohn