Snag: Yes, I took a newb handgun shooting once. She was hitting the ground halfway between her position and the 10 yard target. It wasn't the gun's fault. She'd get the sights on the target, then slowly lower her arms in anticipation of the recoil. We all do the same thing to some degree, it's just that an experienced shooter knows about it and keeps it to a bare minimum.
PB Bob: Even a fairly light load shouldn't put your POI that far off (what, several feet?) at a mere 25 yards. We're talking about a time-of-flight difference of a few milliseconds. Often a lighter load than the one a handgun was "regulated" for will cause your POI to be high at close to medium range. The ball spends more time in the barrel as the gun recoils.
Then again, there is a minimum amount of energy required to overcome friction and push the ball out the barrel. Sometimes the wrong load can result in a ball sticking in the bore, but you usually hear of that happening with jacketed bullets in a .38 S&W or something. If you're just above that energy level, the balls could be dumping out at hand-thrown velocity. I think that is extremely unlikely however. 15 grains isn't all that tiny.
Assuming the gun is in proper condition and properly assembled, and assuming you are an experienced shooter, it sounds like a sight adjustment issue. Can't tell any more without seeing it and firing it. Inspect the gun muzzle to butt. A lot of crazy things can go wrong, but for it to work properly, everything has to go just exactly right all at once.
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