[D.S.Brown]

I have a CMMG 16" Mod 4. Decent rifle but one problem: My Zero.

I followed the instructions to conduct a 25 meter zero. I was shooting from a rest the entire time. All of my shots were grouping nicely, just to the far bottom left corner of my rifle target.

I had to drop the front sight 13 clicks to raise the strike of the round to the proper elevation. What concerns me the most is the rear sight had to be moved 30+ clicks to the right from center. I might have 10 or 12 clicks of adjustment left on the right side. My rear sight appears very far the right.

It is NOT my trigger control because once I made these adjustments I was dialed in dead center on the target consistently.

My concerns. It has been nearly 20 years since my time in the Army. I don't remember making such dramatic adjustments, especially with windage. I understand that I am 42 and not 22, but still I don't think it is my sight, which is quite good.

I spoke to other people at the range who own the same model of CMMG. They are not reporting having to make such adjustments with iron sights. I plan to return to the battlesight zero and have friends shoot to see if they too are so dramatically off.

CMMG says that I can send it back and they will take a look because it is covered by warranty.

Has anyone else dealt with this type of issue? If other people's rifles of the same make are not having these issues, is it possible I a rifle that slipped through QC?

I know it is limited info, but any insights would be appreciated. Thanks,

Best,

Dave

[faawrenchbndr]

Contact CMMG,.....it sounds as if yout FSB is canted.

[D.S.Brown]

faawrenchbndr,

What is an FSB, I think it means Front Sight B........? Thank you.

Best,

Dave

[faawrenchbndr]

Sorry,......frone sight base.

DPMS and a few others had a big issues with this a few years ago.
Seems the front sight base was fitted/reamed/pinned crooked in
relation to the barrel alignment pin.

[D.S.Brown]

Thanks again sir.

Best,

Dave

[JBaird22]

I know of an individual who had two different uppers from CMMG that had their front sight base canted. I am not bashing them (I have one of their guns) but they seem to have this problem frequently.

[D.S.Brown]

The rifle goes back to CMMG on Wednesday. Thanks again all.

Best,

Dave

[AK_Stick]

also check to see if your front sight post itself is bent. I had this with 3 new M-4s before we went to Kosovo.

[hasselbach]

Use a laser sight initially to set your windage, it will tell you if your FSB is cocked early on.

[faawrenchbndr]

Originally Posted by AK_Stick

also check to see if your front sight post itself is bent. I had this with 3 new M-4s before we went to Kosovo.

Wow, I would have never thought of that!