Arms #40 with A2 front site not zeroing.

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[ARCHIVED THREAD] - Arms #40 with A2 front site not zeroing.

Posted: 9/27/2004 8:12:06 PM EDT

This maybe an old horse that most of you are tired of beating, it's a new problem for me. I'm looking for a solution to my model 1 flat top being too high to zero using my Arms #40, with the A2 front sites. Trying to keep the front site post within the ears. The only real solution I'm seeing so far is to switch to a folding front site, or go back to an a2 upper reciever. How do you guys solve this problem??? Doesn't any of these manufactures see potential for profit in marketing rear site that set lower??? Any input welcome. Thanks, Bin.

Posted: 9/28/2004 5:17:36 AM EDT

[#1]

You might consider getting another flat-top receiver to replace the one you have. It sounds like it might be out of spec.

There have been some users that need to swap out the front sight post to work with a folding rear, but if its as far out as you say, swapping out the front sight may not be the answer.

.

Posted: 9/28/2004 5:35:40 AM EDT

[#2]

Typical problem with A3 and 16" barrels. Bushmaster sells a +0.040" front post. Install it and you are good to go.

Posted: 9/28/2004 5:38:56 AM EDT

[#3]

Quoted:
This ismaybe an old horse that most of you are tired of beating, it's a new problem for me. I'm looking for a solution to my model 1 flat top being too high to zero using my Arms #40, with the A2 front sites. Trying to keep the front site post within the ears. The only real solution I'm seeing so far is to switch to a folding front site, or go back to an a2 upper reciever. How do you guys solve this problem??? Doesn't any of these manufactures see potential for profit in marketing rear site that set lower??? Any input welcome. Thanks, Bin.

Perhaps someone with more experience can chime in here, but have you tried the ARMS #40L? I know they have the ARMS #40, #40A and the #40L the 'l" is for the Low Profile model.

Here's a link:

ARMS Low Profile Rear Site

Posted: 9/28/2004 5:48:11 AM EDT

[#4]

Quoted:
Quoted:
This ismaybe an old horse that most of you are tired of beating, it's a new problem for me. I'm looking for a solution to my model 1 flat top being too high to zero using my Arms #40, with the A2 front sites. Trying to keep the front site post within the ears. The only real solution I'm seeing so far is to switch to a folding front site, or go back to an a2 upper reciever. How do you guys solve this problem??? Doesn't any of these manufactures see potential for profit in marketing rear site that set lower??? Any input welcome. Thanks, Bin.

Perhaps someone with more experience can chime in here, but have you tried the ARMS #40L? I know they have the ARMS #40, #40A and the #40L the 'l" is for the Low Profile model.

Here's a link:

ARMS Low Profile Rear Site

My bet is that the 40L has the same aperture height as all the others, so I don't think that it will solve your problem. A front flip sight won't help either. I'm going thought this with a PRI front flip sight with an LMT rear BUIS. I went with the +.040 Bushmaster front sight post and it helped, but it is still higher than I like, as it is above flush somewhat.

Posted: 9/28/2004 6:10:44 AM EDT

[#5]

From what I can see, the 40 L has the same height when deployed, lower when folded. I was hoping to keep the site post from protruding above the protective ears. It looks like I'll be above that height if I use the + height BM post. How about switching to a different gasblock, and mounting a tall folding site that is for use with a railed gas block, to the hand guard. Rather than using a short flipup site that would normally be for the handguard. Will this give us the right height?

Posted: 9/28/2004 7:42:08 AM EDT

[#6]

Maybe the "F" marked front sight tower would work for you. Bravo Company USA sells them. Go to this page and scroll down about halfway until you see New USGI Pre-Ban "F" Marked Front Sight Bases. I imagine you'd need to have a gunsmith do the installation. Hope this helps.

Posted: 9/28/2004 10:53:40 AM EDT

[#7]

Not to hijack this thread, but I've got a RRA Tactical Entry upper (flattop with 16" barrel) and if I have read this thread correctly, if I get the ARMS #40 BUIS, it will not zero properly. Is this correct or have I missed something?

Posted: 9/28/2004 11:00:21 AM EDT

[#8]

Quoted:
Maybe the "F" marked front sight tower would work for you. Bravo Company USA sells them. Go to this page and scroll down about halfway until you see New USGI Pre-Ban "F" Marked Front Sight Bases. I imagine you'd need to have a gunsmith do the installation. Hope this helps.

While this will fix your problem, a FSB swap is no easy task.

Originally Posted by KNEESINTHEBREEZE

Not to hijack this thread, but I've got a RRA Tactical Entry upper (flattop with 16" barrel) and if I have read this thread correctly, if I get the ARMS #40 BUIS, it will not zero properly. Is this correct or have I missed something?

Chances are that you may have problems, as stated above.

Posted: 9/28/2004 1:19:12 PM EDT

[#9]

KNEESINTHEBREEZE,
From what I understand the Arms rear sites are made to use with the Colt, and LMT front sites which are taller than others. I also wonder if the FN front site is also taller like Colt, since FN has a military contract. Does anybody know if this is the case???

Posted: 9/28/2004 1:51:46 PM EDT

[#10]

you need a FST with an 'F' forged into it, that means it is 'flattop' height for your mil spec rear sight or carry handle.
ADCO can do the swap for you, but most likley won't be pinned on, it will have to be setscrewed into place.

[ARCHIVED THREAD] - Arms #40 with A2 front site not zeroing.

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