Load development and point of impact

[The Sodbuster]

I've noticed when working up a load at the range, as I go up in powder weight for a given bullet, I would expect groups to impact higher on the target (given same point of aim) because they're presumably traveling faster and will drop less.  Frequently, higher charged loads impact lower on the target  Seems kind of counterintuitive. 

Lately I've noticed this primarily with my .223 Remington using 50-55 grain bullets.  Can't recall if this has been the case with other cartridges.  Any ideas why?

[rickt300]

With rifle that have little recoil and your charge weights from start to finish vary little like my 22-250 I have noticed very little POI change up or down. With my 30-06 and 358 POI goes up as charges are increased.  I have a 270 that seems to put all loads and most different bullet weights within an inch of each other. It also hits every coyote Ishoot it at no matter what.

[Castaway]

In pistols particularly, slower velocities tend to impact higher than when fired faster.  The reason is the longer barrel time of the bullet allows the muzzle to climb more before the bullet exits.  Add a heavier bullet and the same thing happens.  I can't shoot a 300 grain bullet from my Black Hawk because at 50 yards the point of impact is 15" higher than my point of aim and that's with the rear sight bottomed out.

[Wingman26]

Any time you change anything in a load you can expect a change in the point of impact, differences in powder charges, a different powder,, changing to a different brand of bullet, even in the same weight, it's difficult to predict where a bullet is going to impact with the possible exception of bullet weight, lighter bullets almost always impact lower on the target than heavier ones.  Another thing is that the changes in impact aren't limited to elevation, they often include changes in windage as well.

[Castaway]

Wingman26, how right you are.  I have two accurate loads for my 45 Colt Trapper.  After deer season, I change the sights to use it for plinking and turkey.  When I go to the lighter load, I have to drop the sights 2.5" and go right 1" at 50 yards.  Both use the same bullet, but different powders.