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M4 Sight adjustment windage almost maxed?


Cannon762

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I picked up a Scalarworks mount and RMR for my M4 and headed to the range to zero it with some slugs and pattern with some buckshot.

 

I got the RMR pretty well set and went to adjust the irons to match it, but doing so puts my rear sight one line away from the farthest edge of the left of the sight.

 

Anyone else's this way?

 

My M4 has had a couple abnormalities thus far so my interest is piqued.

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The way that you zero the windage is the way that you do it for an M1 Garand or M14 rifle. First loosen the front sight post and move it to the right or left depending on point of impact.

 

You move the front sight in the opposite direction that you need to move the POI. For example if your shots are going to the left of POA, you would move the front sight post to the left to move POI to the right. If your shots are going to the right of POA, you would move the post to the right to move the POI to the left.

 

That way your rear sight should be able to remain indexed in the middle, thereby enabling you have the full range of windage adjustment in either direction.

 

HTH.

 

edit; on a Garand or M14 moving the front sight post .008 will move POI approx. 1" at 100 yards. There is not nearly as much lateral adjustment available on an M4 front sight post as there is on the rifles I have mentioned but, it can move some.

Edited by Evolution
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Oh hey I'd never noticed it was even adjustable, even has hashmarks and everything. Thank you for this! I will look for the appropriate sized wrench here, looks like 5.5mm according to an older post.

 

Is this in the manual and I just missed it? The sighting section only seems to mention the rear sight.

 

Appreciate the help!

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I don't believe it's in the manual but, that is how it should be done on a weapon that has a lateral adjustment on the front sight. Always start first with the front sight so your rear is kept at mechanical zero, to use just for temporary windage adjustment, then return it to mechanical zero (centered).

 

That way, you will have the full range of the rear sight adjustment either left or right as needed.

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Good info.

 

I will note that there have been cases where the barrels have been canted slightly causing the sight alignment issues. Users have sent the barrel assemblies back to Benelli and I believe they simply replaced the barrel rather than trying to make adjustments barrel extension.

 

Yep, over indexing (timing) or under indexing a barrel will cause shots to place right or left of POA. Very common problem with the Garand and M14 type rifles.

 

To the OP; Re-reading your post made me realize something (if I understand you correctly). You don't want to try and match your iron sights to the zero of your optic, not that you would even be able to match them, (the optic has waay more adjustment) but rather, the irons will be set to a zero for the gun, and then when using your optic, it will have it's own separate zero for the gun.

 

If you were trying to match them to each other, no wonder you ran out of adjustment on the rear sight platform.

Edited by Evolution
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If you were trying to match them to each other, no wonder you ran out of adjustment on the rear sight platform.

 

Can you clarify on this? I have co-witnessed red dots to irons on almost every other long gun I own without issue.

 

I got the wrench in today and just moved the front sight one hashmark to the right and all seems correct now.

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