This is defiantly something you do not have to worry about. IF you're younger, you could be a late bloomer, and puberty wouldn't have kicked in yet. Also, frequent masturbation tends to result in less "shooting" just because of the demand. If you're older, don't masturbate for a few days and then try, you probably will shoot further. And then there's some people that just don't shoot that much. I'm one of them, it's not a problem really.
And a side note - If any of the conditions that result in less shooting are true to you, it's not unhealthy or bad so it doesn't matter all too much.