Bullet drop depends how far away you are and which weapon you're using. Don't think there's any other factors. Although shooting high sounds weird--are you looking at the wrong place in the reticle or something? For an average shot at or below optimal distance, it should be in the center of the reticle. Another possibility is server lag, displacing where you and your target actually are in the game's mind.
That said, note that on anything other than a sniper rifle, such a good scope will probably be a waste. Assault rifles, etc. aren't meant for such an extreme distance and will be terribly inaccurate, on top of whatever bullet drop is happening.
Here's a chart on weapon stats, although it might be a little different by now; not sure. Just to give a rough idea on what they can do.
https://pubg.me/ <- is probably the best resource for weapon damge/recoil/bullet velocity etc. As well as player stats