At ten yards, it is not the ammo, unless they are really crude reloads. In general, small, more or less random, errors tend to add up, usually cancelling each other out somewhat, but out of a hundred rounds, you will occasionally have all these small random errors acting in the same direction, and that shot may be farther out than usual. That is NOT what is happening here. If you are more than a couple of inches out at ten yards, YOU did something. Some of the ancient charts used by beginning bullseye shooters may give you the answer, but it is more often helpful to have some competent personal shooting instruction. At some point you will probably want to shoot at 25 yards, or at least use an NRA 50-foot bullseye target at 50 feet.

Best wishes!