Guys, point-of-impact is NOT due to the bullet dropping quicker!!! (Well, at least not at typical handgun defensive distance, anyway.)
All else being equal, the bullet that leaves the barrel sooner, has a LOWER point of impact, because the muzzle has not yet risen as far. Lighter bullets generally leave the barrel sooner, for several internal ballistic reasons. Simple as that.
180-grain Gold Dots shoot to point of aim in my SIG P229 pistols. Everything lighter shoots lower. Much as I like the apparent power of some of the hotter 155/165-grain loads, I have to allow for their lower P.O.I.
The same dynamic is at work in .357 Magnum. I like hot 125-grain loads in my adjustable-sighted GP100s, but tend to use heavier-bullet loads in my fixed-sight revolvers. Only the adjustable-sight guns can be adjusted to the P.O.I. of the lighter bullets.
All else being equal, the bullet that leaves the barrel sooner, has a LOWER point of impact, because the muzzle has not yet risen as far. Lighter bullets generally leave the barrel sooner, for several internal ballistic reasons. Simple as that.
180-grain Gold Dots shoot to point of aim in my SIG P229 pistols. Everything lighter shoots lower. Much as I like the apparent power of some of the hotter 155/165-grain loads, I have to allow for their lower P.O.I.
The same dynamic is at work in .357 Magnum. I like hot 125-grain loads in my adjustable-sighted GP100s, but tend to use heavier-bullet loads in my fixed-sight revolvers. Only the adjustable-sight guns can be adjusted to the P.O.I. of the lighter bullets.