Sighting Questions [Archive] - Glock Talk


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03-01-2010, 11:36
I need work. A good deal of it.

Took my AR (BCM 16" w/ Troy BUIS) to the range for the fist time this weekend. Went though 100 rounds 55gr.

I usually shoot at a friend's home/range, but as he's out of town I went to the public range. I had planned on IBSZ at 50 yards, but they only had 25 and 100 on the rifle range.

At 25 yards, I could keep mostly in the black, but I have about zero groups. I only shot a few rounds out to 100, and nothing (targets were downloaded and on printer size paper). Now, I later realized that going from 25 to 100, the round is still climbing, so I could have been close, but over (with no way to tell, small target). At least, this is what I'm thinking, and had I aimed a little lower, might have seen some hits. Anyways, back to the 25 yards...

As I said, mostly in the black, but mostly no groups. I still plan on IBSZ at 50 when I get the chance, but looking for some pointers.

Along those lines, some clarifications....

BUIS: Large aperture for 0-200, small for anything further.

Site picture: POA should sit on front site post.

Front site adjustment: Moving clockwise (UP) moves POI up.

Eotech: Once I've established IBSZ on the irons, placing the dot on the top of the front site should be gtg for a starting point to zero it.

Am I being to hard on myself for the first time shooting this rifle, or is this to be expected?

To add..this was sitting, shooting from bench using backpack as a rest (not the best, I know).

What type of groups should I be expecting and how soon, at say 25, 50 and 100 yards?


03-01-2010, 16:17
If you zero your AR at 25 yards, it will shoot about 5 1/2" high at 100 yards and be close to right on at 300 yds. Some guys, myself included, zero at 50 yards instead. Much has been written about this and you might want to try that if you can. There is an online ballistics calculator that can help you figure out hold overs or scope adjustments by simply entering in the specified data and it does a work up for you free. As far as group size, it's hard to say depending on your bullets, barrel set up and your ability. Most people would say 1.5" to 2.0" groups out of an AR carbine at 100 yds is pretty normal.

03-01-2010, 16:25
Front site adjustment: Moving clockwise (UP) moves POI up.

Just noticed this. You want to move the rear sight in the same direction you want your bullets to impact and the front sight the OPPOSITE direction. Best of luck.

03-02-2010, 07:36
Just noticed this. You want to move the rear sight in the same direction you want your bullets to impact and the front sight the OPPOSITE direction. Best of luck.

Are you sure about that? Everything I've been told and have read is that you move the front sight in the dirrection you want impact.

Thanks for the info. I intend to do a 50 yard zero when I get the chance.

03-02-2010, 08:22
Get thee to an Appleseed! Its quite the eye-opener for most shooters, and the basics of position shooting are all we teach. Sitting, standing, and prone...the 6 steps to firing the shot...breath control...inches, minutes, clicks...and a good dose of American history and our heritage as Riflemen, to boot.

Check the link in my sig; it would be the best $70 you can invest in a weekend of shooting instruction.

FWIW, front sight down equates to raising your groups on the target. Rear sight adjustment moves the group the same direction as you move the sight. 'Rear is right, front is wrong' is the way I remember it. (if you move your front sight, groups move the opposite direction, whereas moving the rear sight moves the group the same direction)

I'd also refrain from adjusting my rear sight while working on my zero. Test after test has shown that doctrine is wrong; flipping that little sight moves your windage as well as changing the diameter of the hole. Pick one, stick with it. I'd recommend the 0-200 sight and a 50yd zero.


03-02-2010, 09:40
Ok, I'm confused. After reading this...

•To raise the next shot group, rotate the front sight post in the direction marked UP (clockwise)

I read that as to move my shots up, turn the front post up? But, the two of you tell me to lower it (which, as I think about it, makes more sense). As I think about it, lowering the post, would mean "raising" the rifle to compensate from the lowered sight, which would make my shots go up. Right?

So the marking "UP" mean it puts the post up, but my shots down.

03-02-2010, 09:42
I'd recommend the 0-200 sight and a 50yd zero.


On the Troy, 0-200 is the the larger, correct?

03-02-2010, 10:05
Pick one, stick with it. I'd recommend the 0-200 sight and a 50yd zero.


All good info, but I'd recommend the small aperture for everthing except:

1) Pro Mask Fire
2) Back-up Use
2) CQB

03-02-2010, 10:29
More confusion...

In this video:

They are turning the front site up, to raise impact (@ 2:30).

03-02-2010, 10:41
The 'UP' on the front sight post turns it clockwise, no?

Clockwise is 'right', correct?

'Righty-tighty, lefty-loosey', no?

So, by turning the front sight clockwise, are you not physically lowering the sight post in the sight itself? Therefore, the front sight is going down, but your groups would be going up.

Too much thought = confusion.


03-02-2010, 10:48
When they say, "Turn it up" they mean to follow the UP arrow marking, which is really down.

Rear sight chases POI, Front sight is opposite.

03-02-2010, 11:05
Too much thought = confusion.Byrdman

That's it, I've managed to confuse myself. Thanks guys, you've un-confused me.

Rifle shoots low= Follow "UP" which turns post down. Shots now higher.
Rifle shoots high= Turn post counterclockwise, post goes up, shots go down.

UP means shots go up, not the post. I think that was some of my confusion.

Thanks for the help.