I purchased a mosin-nagant at one of the local gun shops and for some reason the first time that I took it out, at 50yds. it shoots almost 20in. high. I assume the front site post is too short, but I don't know how i can remedy this...
That thing will shoot somewhat high at 50 yards anyway, but not that high. Get a piece of small diameter shrink wrap tubing and stick it on the front post. Trim as needed get zeroed in.
that's awful high, but they do that, man. I have three. If i'm popping milk jugs with them at 30 yards, I need to practically aim at the bench they're sitting on. Those guns are made to reach out there! you see how high that rear sight goes
i was using an approx 2'x3' piece of plywood at 50 yards and i had to aim about 10" below the wood to hit the middle, so it might even be more than 20"
Mosins are typical of battle rifles of the era and they are battle zeroed for 300 meters. They will shoot high at any range inside of that. Also what type and weight of ammo you are using will also impact its zero. I read an article about replacing the front sight with a taller one made of a thick wire. I'll find a link for you.