FN Herstal Firearms banner

1 - 7 of 7 Posts

·
Registered
Joined
·
55 Posts
Discussion Starter #1
I am trying to zero my iron sights at my range, I have access to 25 and 50 yards. I tried zeroing the rifle at 50 yards but the front sight post didn't go down low enough to get me within 8" of the target. I know from reading the manual that it wants a 25m/300m zero. I did leave the rear adjustment at 3 at the time.

I will never be shooting it at 300m but my buddy has a range that goes out to 200 yards that I would use from time to time. My question is, how do I adjust the rear sight in order to zero the rifle at 50/200yards. Do I drop it to 2 for 200 and then make the rest of the adjustments on the front sight.

Has anyone else zeroed the rifle at anything other than the 25m/300m and have some recommendations.

Thanks,
Drew
 

·
Registered
Joined
·
117 Posts
Set your iron sights to 100 yards, adjust so your point of impact is 1 1/2" low at 25 yards. You should be good at 100 yards POA/POI. To shoot at 200 yards adjust rear sight to the 2 position and so on for 3,4 etc..
 

·
Registered
Joined
·
55 Posts
Discussion Starter #3
Set your iron sights to 100 yards, adjust so your point of impact is 1 1/2" low at 25 yards. You should be good at 100 yards POA/POI. To shoot at 200 yards adjust rear sight to the 2 position and so on for 3,4 etc..
So for zeroing at 100, what should the rear sight be set to? Thanks
 

·
Registered
Joined
·
117 Posts
For zeroing set the sight for 100 yards at the #1 position. Then adjust that sight adjustment to shoot 1 1/2" low at 25 yards. At that point you will be zeroed in at 100 yards with the rear sight at #1 position. After that if you are using the proper weight and velocity ammo you should be on at the given zeros as you rotate the rear sight. I say should be because the numbers may not correspond with the bullet weight and velocity. They should be close enough for a man size target at the given distances.Remember you are adjusting a rear sight that has given elevation distances, so after the 100 yard zero at the #1 position, the rest is just turn the rear sight for the given distances. 2 for 200 yards 3 for 300 yards and so on. On my SCAR 17 it goes to 600 yards and with the prescribed ammo, it's pretty darn close.
 

·
Registered
Joined
·
12 Posts
BUIS zeroing is addressed in the manual starting at page 2-59 (page 151 of the pdf).

You start by verifying that the sights are at mechanical zero. For the rear sight, which has a total of 36 clicks available, that's 18 clicks from either side. For the front sight, the base should be flush. The small aperture is used for zeroing.

If you're zeroing a 10" barrel, the rear sight should be set to 2 (which will yield a 25/200m zero). If you're zeroing a 14" or 18" barrel, the rear sight should be set to 3 (which will yield a 25/300m zero).

All other adjustments are made in the front sight. Each click of front sight elevation will move point of impact 3/8". Each click of front sight windage will move point of impact 1/4".

Zeroing is conducted at 25m. There's a table in the manual that shows how low the point of impact should be relative to the point of aim. With M855, the 10" barrel should be hitting 4.6 MOA low at 25m. The 14" or 18" barrels should hit 3.2 MOA low. I'm not sure what the MOA actually come to, but it looks like about 25mm or 1" on the zeroing target.
 
1 - 7 of 7 Posts
Top