At what distance are you sighting the gun in? That does make a difference in changes of POI, when you run the adjustments.
When I am sighting in a new gun, I begin at 10 yds, as that is about where the ball or bullet furst crosses the line of sight. I make my adjustments to windage there, and then adjust the elevation until the ball or bullet is hitting about 1 " low from POA.
Then I move back to 25 yds, which is still close. I use a small bull, and try to have the ball hit 1 inch high, but adjust the windage again to center the hits. I start with a caliber load of powder under a round ball, checking the patches to make sure I am not tearing or blowing holes in them. At 25 yds, I can actually work down from that caliber load( ie. 40 grain is a .40 caliber rifle, 45 grains in a .45 cal. rifle, etc.) to find a light load that will make a nice 3 or five shot one hole group. Again, at that stage I am just trying to get my groups centered; I will work on finding the best 25 yd. range load later.
Then I move back to 50 yds, and repeat. Usually I have only a fine adjustment to make with the windage, and I can work up a good grouping load at that range, and " zero it " at that distance if I want. Again, I am shooting targets, and am not interested in this stage at developing a " Hunting load ". The caliber load seems to work well, within 10 grains or so, at being the best target shooting load at that range.
Then I move the target out to 100 yards, and find out where the POI is at that range, and how well the load groups at that distance. I smoothbores, the groups open substantially, over what I had at 50 yds. With rifles the groups will be not quite double the size of the 50 yd. group, assuming everything else is right. If the gun is going to be used for hunting, I take the time here to increase the amount of powder in 10 grain increments to find out what seems to shoot the most accurate, and flatest. Using FFg powder, that seems to be approx. 1 1/2 times the charge that worked best at 50 yds, with adjustments downward on shorter barreled guns. Once you get over .50 caliber, the balls are so heavy that you don't really need to load lots of powder for them to penetrate or killw large game well. So, I work on accuracy rather than velocity.
As to how much elevation adjustment a given sight will permit, it very much depends on the range at which you are shooting. at 25 yds, you should get about 4 inches. That will keep you on a piece of notebook or typing paper at that distance.
But, Start your shooting with a new gun, or new sights, at 10 yds. You learn absolutely nothing about your sight settings if your ball misses the target all together.
My late, and good friend, M. Don Latter was sighting in a .62 Cal, custom made rifle one day when I arrived at the range. He was in a foul mood, as he had been shooting the gun off the bench at a 25 yd., 8 " bangplate, and had not hit it yet, after shooting many balls. While explaining to me and others what he had tried, ( shooting around the clock, changing powder charges, among other things) to get a shot on the bangplate, he managed to dry load a PRB in the gun. ( No powder!) He instantly blamed me, because I was talking to him as he reloaded the gun!
This was a flintlock, and he could take the vent liner out, so I got two screwdrivers from my kit, one large one to remove the liner, and a very small thin one to use as a lever( ouch!) to try to push that PRB forward enough to get some priming powder behind it. I managed to wedge the ball forward only about a 32nd of an inch, but he got a few grains of powder behind it, and put the vent liner back in the gun, then put the lock back on. Then Don primed the pan, and instead of just firing the ball out into the ground, he sat down at his bench, rested the gun over the sandbags, took careful aim at the bang plate, and squeezed the trigger.
Well, the pan flashed, the main charge fired, in a whimpy sounding pop, of course, and damn if that round ball did not hit the EXACT center of that bangplate at 25 yds. We were all speechless. I took the opportunity of that pregnant pause to dryly comment to Don that we had found out what his problem was with the gun hitting that target: His head whipped around to look at me, the other guys looked at me, and I answered:
" You obviously were using too much powder !"
Needless to say, everyone, including Don, got the giggles over that one. We did put up a paper target at 10 yds, with lots of paper, so that we could find out where those sights were shooting, and he quickly made the needed adjustments to bring the sights on target with standard loads.
But, around my gun club, anytime someone can't hit a target at 25 yds, someone is likely to mutter, " He's obviously using too much powder!"
