Canted FSB

[TheRealDonJohnson]

I have a rifle I built and I think the fsb is canted slightly to the left. Should I send it to a shop to have then work on it or is there somehing I can do besides bringing my rear sight all the way left. I shot it last Friday and it grouped to the left.

[jakebrake]

I have a rifle I built and I think the fsb is canted slightly to the left. Should I send it to a shop to have then work on it or is there somehing I can do besides bringing my rear sight all the way left. I shot it last Friday and it grouped to the left.

is it a Kalashnikov, by any chance?

[Tank50]

If everything else is straight a front sight left side cant would most likely cause the rifle to group to the right. Could there be another reason it groups left such as the crown? Are the rear sights straight?

[TheRealDonJohnson]

I suppose it's canted to the right then. And no it is an AR. I assembled the lower myself and let it sit in the safe for a few months. My buddy had a spare upper, mid length 14.5 pinned and welded w an a2 front sight. I slapped it on my lower and took it out the other day. It was all to the left of the target.

[dkf]

Did the notch in receiver get damaged and allow the pin on the barrel to move off to the side? If the FSB is pinned on cockeyed that will be a harder to correct.

[TheRealDonJohnson]

Did the notch in receiver get damaged and allow the pin on the barrel to move off to the side? If the FSB is pinned on cockeyed that will be a harder to correct.

I am not sure. I guess my best bet is to send it to adco or somethjng. I will call in the morning

[Gun]

Take the upper apart and see if there is some wiggle room with the indexing pin on the barrel. If you have to, you can file the slot on the upper, allowing the barrel to turn ever so slightly to the left (looking toward the FSB). Adjusting the FSB can be a bad idea because of the alignment with the gas port.

If you really want to say you 'built' an AR, accomplish this, otherwise start with stating that the upper you got from a friend is foo-dangled, what should I do?

Also, You could always cut down the FSB and add a free float HG.

[bug]

How far "off" is it? What type of rear sight do you have? Does the FSB "appear" to be canted? If you stand the upper upside down does it wobble?

Bob D

[TheRealDonJohnson]

How far "off" is it? What type of rear sight do you have? Does the FSB "appear" to be canted? If you stand the upper upside down does it wobble?

Bob D

The fsb doesn't "appear" to be with the naked eye. I am using a removable Rock River a2 carry handle. It is all the way over to the left on windage. I stood the upper upside down with and without the carry handle a2 rear sight on a glass table and it has slight wobble.

[dkf]

Best to try and use the flat top of the receiver to gage the straightness of the FSB. The clamp on carry handle could be flawed. Maybe throw on a BUIS that you know is good to go and see if you can repeat the issue before spending money to send it off.