Bushmaster sight issues

[farmer2]

Hello,
Just traded for my first AR (Bushmaster flattop). I purchased this rear sight http://www.cheaperthandirt.com/ARR140-47756-1887.html . With the rear site all the way down, the front sight still had to be adjusted so high that the spring loaded detent was to low and not functioning. The rear sight also had to be moved to the left one hashmark of center to be zeroed correctly. My questions are,

1. Is this the wrong rear sight for my bushmaster?

2. This gun will be primarily used for coyote hunting with a hi-power scope. Is there a front sight I could install myself that will flip down during hunting that would match up better with this rear sight?

Sorry if I am using improper terminology, I am new to the AR game. Any feedback you can give will be very helpfull


Thanks

farmer

[farmer2]

I found this on bushmaster's site http://www.bushmaster.com/shopping/bmas/yhm-9370k.asp , would this work for replacing my current sight? How difficult is it to remove the front sight, and install this gas block?

thanks


farmer

[Ljunatic]

I believe that there is a front sight post .040" longer to compensate for this problem.http://www.bushmaster.com/shopping/scopes/9349056-m.asp

[farmer2]

Thanks Ljunatic! I still think I would like to switch to a flip-up front sight eventually. Do you know how difficult it is to remove the front sight?

Thanks

farmer

[njl]

That rear sight (boy, that's cheap) is basically a cut carry handle. Unless it's improperly adjusted or way out of spec, or your barrel was poorly installed and shoots way high, your normal front sight post should have worked with it.

Did the AR come with a removable carry handle?

If you put a big scope on it, once you get past a few X magnification, the front sight post will disappear. I wouldn't worry about it.

[USMC79to83]

This is based on my limited knowledge - all standard disclaimers apply..

Bushmaster does not use a "standard f-marked" front sight base. Ljunatic offered the best solution, I think.

Replacing the front sight assembly with a railed gas-block (for a flip-up sight) is a good option. However, I've read that the Bushmaster fsb is ON THERE and can be more challenging to remove than some others.

[farmer2]

Thanks for the feedback guys. As I looked further into removing the front sight, I've decided I will let me gunsmith tackle the job. I'm skeptical that a sight .04" taller will make that much difference, because the front sight is adjusted much higher than that above the detent. It would help but still not shoot properly. Hopefully, it is my cheap rear sight that has an issue and not the rifle :( I wish I knew somebody who had a bushmaster carry handle I could try, because that would let me know right away.

thanks

farmer

[DT]

I think it is a common but unpredictable problem whenever you use a BM barrel and a flat top upper reciever. I have had 3 BM barrels and they all have needed the taller FS. Fortunately for me none extended past the ears of the FS after sighting it in. Changing the front sight is very easy. You do not need a gunsmith for that. All you need to do is to uncrew the old post and screw in the longer FS post. I would not go through the trouble of fitting a new front sight base.

Some back up iron sights are sl. lower than others. I had less of a problem with a Troy and MI flip up rear sight than I did with a comparable GG&G version. Unfortunately you will need to experiment with different sights to see which works best for you. An A2 upper receiver probably would work even better if you do not mind not having a flat top.

[ColoradoPacker]

I have NO problems at all with the STOCK front iron sight height on my BushMaster flat top M4 A3 using a Wilson Combat rear flip up BUIS. However, the Wilson sight was probably $150, not $25.

I didn't have to change the front sight one bit, and I get perfect co-witnessing with my OETech 512 if the rear iron sight is up.

[njl]

Originally posted by USMC79to83
This is based on my limited knowledge - all standard disclaimers apply..

Bushmaster does not use a "standard f-marked" front sight base. Ljunatic offered the best solution, I think.



I've got 2 Bushmaster flat tops. One has an F marked FSB. The other has no markings other than a sort of logo mark. Both zero'd just fine with the included carry handles.