Jbotto,
I think Jim covered it.
I'll note that while rifle shooters argue about whether or not to crimp, they are talking about jacketed bullets, which have a lot more friction with the case mouth than a lubricated lead bullet does. Also, they don't usually have their cartridges in a cylinder, which tends to pull the cases off the bullets in recoil because its recoil transfers to the cartridges at the rim. When you you have a force backward against the rim, but nothing pushing the bullet, that's the same situation as inside an inertial bullet puller. In a rifle magazine recoil is usually against the nose, tending, if anything, to push bullets in rather than pull them out.
You can get away with no crimp in a revolver if the load is very light or the gun is very heavy, but only up to a point. As an extreme example, a friend of mine has one of the super light titanium revolvers in .45 Colt. He is a big guy with massive hands, yet he swears he cannot load any round with a bullet heavier than 200 grains, because at 250 grains, even with jacketed bullets, no amount of crimp prevents the bullets from backing out until they protrude from the chambers and jam the cylinder.