Some readers are using a BUIS as the primary sighting system for their rifle. Be it cost or just saving up for a quality optic… or they may like the KISS principle.
This post I hope will provide some insight as to the capabilities of a 50 yard zero in conjunction with a non adjustable BUIS.
When I got started with my goal to shoot longer distances accurately and repeatably but I would get really hug up on the projectile weight in relation to my adjustable carry handle. Only when I finally put the bullet drop to paper did it make me realize how much I fretted over nothing. I hope you forgive the uglyness of the picture I am about to post but I post it for good reason:
As you can see with a simple 50 yard zero your rifle can still get hits on targets out to 350 yards with either loading. The red dot would be the aiming point from 0-350 yards. At 400 yards the drop gets iffy so consider the holdover needed to reliably put rounds on a target at that distance would require one to obscure the target with the front sight post. Past 350 a single non-adjustable BUIS would be out of its league.
Don’t hesitate to visit a carbine competition with only basic equipment. The chances of having to shoot past 300 might be fairly low or only a stage or so. In the meanwhile you will learn much while you save up for that ACOG.