M4 bushmaster(civi model) rear sight too to left how to fix?

[Gpere54]

I saw the C products magazines. Which should I purchase the aluminum or steel?

[C4IGrant]

I saw the C products magazines. Which should I purchase the aluminum or steel?


Get the SS ones. They are much better. I just got some in stock and offer M4C member discounts on them.



C4

[CV-23]

Just repaired mine tonight after reading this thread. The front sight will only rotate a bit left or right. The milled cuts in the barrel will only allow "some" adjustment. This keeps the gas port somewhat centered and operational. My 11.5" CAR 15 front sight was canted left and took 20 clicks (out of 30) left to zero. It now only takes 10. Not perfect but alot better. Not sure who made this barrel (no markings and not even a proof mark)....shoots great with Reloader 7 (no flash) and has tons of muzzle flash with 335 ball powder on humid days. This upper came on a used Bushmaster Lower that was like new. The Upper in an Olympic Arms and fits perfect to my lower. I had my Gunsmith check the mounting/headspace on this barrel and it was off a bit. At first I was 30 clicks left! With his help and my tinkering....she shoots better now. It's nice to have an Indoor .22 Range at my house to do some testing. My Colt .22 Conversion worked great in only a 10.5" barrel. I'll fire some 5.56 on Monday for her final shake-down cruise but she looks good for now, Mike.

[Gpere54]

Just repaired mine tonight after reading this thread. The front sight will only rotate a bit left or right. The milled cuts in the barrel will only allow "some" adjustment. This keeps the gas port somewhat centered and operational. My 11.5" CAR 15 front sight was canted left and took 20 clicks (out of 30) left to zero. It now only takes 10. Not perfect but alot better. Not sure who made this barrel (no markings and not even a proof mark)....shoots great with Reloader 7 (no flash) and has tons of muzzle flash with 335 ball powder on humid days. This upper came on a used Bushmaster Lower that was like new. The Upper in an Olympic Arms and fits perfect to my lower. I had my Gunsmith check the mounting/headspace on this barrel and it was off a bit. At first I was 30 clicks left! With his help and my tinkering....she shoots better now. It's nice to have an Indoor .22 Range at my house to do some testing. My Colt .22 Conversion worked great in only a 10.5" barrel. I'll fire some 5.56 on Monday for her final shake-down cruise but she looks good for now, Mike. What kind of tools or how did you fix it. Did you have your armorer do it or something you could do yourself.

Also on a side note. I did buy those brownwells magazines but it won't feed the last two rounds very well. It will do it sometimes and not. And there is nothing wrong with the rifle. I went the range and had it not feed. Then I had some headstrong(mr. know it all) tell me I didn't have the rifle clean. When I had just cleaned it before I got to the range but I had shot 200rds and switched to another range. Well the guy took it apart the bolt and then put his finger on it and said it shouldn't be this color. :rolleyes: duh because I just shot through the thing . Well the guy was a pain in the rear to get off my back. I got home and cleaned the rifle(1hr) and I had it inspected by an NCO on a base near by who is a good friend. He said nothing was wrong with it and looked at my cleaning job(I hate second guessing my self but I like getting someones opinion). I came home and started loading rounds into my two new brownwell magazines and noticed that my BM magazine feed all and ejected all. My brownwell magazines stopped feeding the last two rounds. The follower seems to be getting stuck from the rear. I plan on filing a little then putting some silicone on it. If that doesn't pan out i'll just return them.

[cz7]

well the early days fix for whole a2 left turn thingy was to drll and tap no.6 tapered top allen and washer pushing the sight left sidw of the sight . back to a truer center backing zero from app.2 clicks left to center !

[JLM]

Had this same problem. Sent the upper back and got a replacement. This was a couple years ago at least, and I was told they started using a laser boresighter :rolleyes:

Sent a LMT back for the same reason.

Some people don't mind it, but to me its not conducive to getting a quick sight picture.

[CV-23]

I was able to just use a punch and a wood mallet. The sight rotated a bit right but I'm still about 15 clicks off left (better than 25 I guess). It will only move that far due to the cuts in the barrel. I read somewhere the alignment pin may be bent where the barrel attaches to the upper. It happens if the barrel is over torqued. My upper was not put together very well the first time I guess. My armor trued it up and didn't see a bent pin so who knows at this point. The pin can be replaced I've been told. Funny....I checked one of my Colts and the rear sight is a bit left. How hard can it be to get it right? I shot the rifle on Sat and it still runs perfect feeding everything from Wolf, WWWB, Fed FMJ and GI Ball....Mike.

[Gpere54]

I was able to just use a punch and a wood mallet. The sight rotated a bit right but I'm still about 15 clicks off left (better than 25 I guess). It will only move that far due to the cuts in the barrel. I read somewhere the alignment pin may be bent where the barrel attaches to the upper. It happens if the barrel is over torqued. My upper was not put together very well the first time I guess. My armor trued it up and didn't see a bent pin so who knows at this point. The pin can be replaced I've been told. Funny....I checked one of my Colts and the rear sight is a bit left. How hard can it be to get it right? I shot the rifle on Sat and it still runs perfect feeding everything from Wolf, WWWB, Fed FMJ and GI Ball....Mike.
Ya I saw somewhere that it was the problem some guy said to take a jewlers file to the alignment pin till it straightens. I read it on AR15.com some guy made a book for dummies but for AR and how too's. So I guess i'm going to have to be my own armorer. But I plan on getting a diffrent upper receiver soon because i'm not a real fan of the heavy barrel its just too...heavy. I plan on getting the patrolman rifle upper receiver then I plan on fixing the heavy barrel one. I just hope they don't screw up the patrolman upper either.

[JLM]

Gentleman,

Send the stuff back. Likely culprit: the pill holes were not drilled indexing properly off the barrel index pin, so the FSB itself is canted.

Make them send you another upper, or rebarrell it. They did it for me :p

[BravoCompanyUSA]

some info on sight alignment on AR15 rifles and carbines (https://www.m4carbine.net/showthread.php?t=14)

[combatvet]

I say canted FSB or you just aren't keeping a good cheek weld, nose to CH. If it isn't the gun it's the shooter.

[Gpere54]

I say canted FSB or you just aren't keeping a good cheek weld, nose to CH. If it isn't the gun it's the shooter.
Not me. WHY? Because I had two ARMY and one former Marine shoot the rifle to see if I did something wrong. And no there wasn't. So I'm doing it correctly.