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Discussion Starter · #1 ·
Finally took my new XCR out to shoot today!

I had a great time. The rifle performed flawlessly, was accurate, and comfortable to shoot. I was able to zero my EOTech quickly and without problems.

Unfortunately, I had a problem with my flip-up BUIS from Midwest.

The rifle was shooting a bit low and when I went to adjust the front sight post I was only able to get two or three clicks downward. Not even a full turn as there are four adjustments per rotation. I tried using a bullet tip and finally two nails that I had with me. Of course, I chewed up the finish on it, but that's another issue. :duh:

The detent pin will go down, but the post itself won't turn.

I'm going to see if I can get a real front sight adjustment tool, but I've never needed one before with any of the many front sight posts I own personally or on the ones I shot in the Army.

Any advice? Is this normal for these? Am I doing something wrong?




-K
 

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Is the front sight post base flush or buried in its well? Sounds like there may be a burr or some foreign debris wedged in there, hopefully it wasn't cross-threaded. If you take a wooden pencil w/ eraser (brand new works best) and wedge it on the front sight post and use a small punch or some other poking device to hold down the detent you'll be able to unscrew it easy and take a look. Screw it back in the same way. It usually only works once per pencil though. Old armorer's trick.
 

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Thanks for posting this question and reminding me that I had the same problem when I tried to adjust my sights to correct an initially low POI.

I'm going to try the pencil trick and see what's going on in there.
 

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My MWI front sight went down about 13 clicks, but the gun still shot very low. I filed about 1/16 off, and it's better, but I need to take off another 1/16 or so.
 

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TAKE THE POST OUT, PUSH DOWN ON DENTENT & UNSCREW POST TILL IT COMES OUT. LET UP ON DENTENT & LIFT DENTENT & SPRING OUT. LOOK AT THREADS ON POST & INSIDE SIGHT FOR BAD SPOTS. PUT POST BACK IN WITHOUT DENTENT & SPRING. RUN POST BACK DOWN & SEE IF IT WILL BOTTOM OUT IN SIGHT. MIGHT NEED TO RETHREAD POST & OR POST HOLE IF IT DOESN'T. PUT BACK IN REVERCE ORDER. USE A LITTLE OIL ON THEARDS WHILE DOING THIS.
 

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I'll tell you what I found out: My post was bottomed out in the hole.

When I removed the post and the detent button, the screw threads were clean and normal. I screwed the post in without the detent button and it bottomed out right where I had it before I started this.

I'm going to have to grind off a few threads from the bottom of the post just so I can adjust enough elevation to get zeroed. As it is, at fifty yards it's pretty close, but I have to cover the target with the post to get it there.
 

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Discussion Starter · #7 ·
Is the front sight post base flush or buried in its well? Sounds like there may be a burr or some foreign debris wedged in there, hopefully it wasn't cross-threaded. If you take a wooden pencil w/ eraser (brand new works best) and wedge it on the front sight post and use a small punch or some other poking device to hold down the detent you'll be able to unscrew it easy and take a look. Screw it back in the same way. It usually only works once per pencil though. Old armorer's trick.

Thanks for the pencil trick! I'll try is as soon as I can. The sight started flush at zero adjustement, and like I said, I got less that one full turn out of it. I might have to try to return it if I can't get it to work, but I'll see what I can do.



-K
 

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You can either file down the post or the threads to get more adjustment out of it. I'd recommend the post since those threads can get boogered up easy. It won't take much filing though. But, as a precaution I'd order a spare from Midway or Brownells or somewhere just in case; should still be $4-5, give or take. File little and check often! If you have a laser boresighter or some similar device it'll make it easier too. A lot of match shooters of M1's and M1A/M14's have to do this, it's called "targeting the sights" IIRC.
 
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