With a couple of assumptions...

by Hoot , Diversityville, Liberal-sota, Friday, June 12, 2015, 20:37 (3392 days ago) @ Murphy

Sight height 0.5"
Muzzle velocity 1300fps
Bullet weight 40gr

Sighting in at 50 will have the bullet path within 1" (+/- 0.5" from point of aim) from muzzle to somewhere between 55 and 60 yards. About 2.25" low at 75 and around 6.5" low at 100.

Same thing but sighted in at 75 will have the bullet within about 3.2" (+/- 1.6" from point of aim) out to between 85 and 90 yards and 3.5" low at 100.

Of course, changing the sight height, bullet weight or velocity will push those numbers around a bit.

Great calculator here => http://handloads.com/calc/

I can only get it to format correctly in IE. Firefox does some weird things with the tables. Haven't tried any other browser.

Have fun!