front sight detent is permanently retracted

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Arkane
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Tue Dec 26, 2017 4:19 pm

firearms wrote:
Tue Dec 26, 2017 11:18 am
The A1 adjustment tool works.
https://www.amazon.com/gp/product/B00IO ... UTF8&psc=1
As a rule, because this series of rifles were developed based on the M16A1 spec so there are a lot of left-over features, when in doubt, try A1 stuff.
Will that tool work on the newer front sight posts (like the one pictured on the left vs. the original on the right)? All of the tools I posses have way too short prongs to push the detent down while turning.

Image


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rchen404
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Tue Dec 26, 2017 4:58 pm

Hi Arkane, that's my problem too. I unscrewed the fsp and I have the one with the wide drum (left one in your pic).

So the left wide drum is the "tall" sight? Instead of widening the drum, they should have just made the rest longer. The overall beefy build of the gun reminds me of my AKs more than ARs.

Let me know if you find a tool that works. Otherwise I'm stuck using a stitch ripper and dental pick. I expect an ar sighting tool to work - I hate improvising
Last edited by rchen404 on Tue Dec 26, 2017 10:23 pm, edited 1 time in total.
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e292644
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Tue Dec 26, 2017 5:20 pm

@rchen404
You mentioned on earlier post "The sight drum is flush with the hole" which made me think they installed FSP all the way down to the bottom which will cause detent to being pushed down to the limit.
Please remove it and inspect all parts and make sure spring tension still good.
Install FSP only half way down after see if that will help.
rchen404 wrote:
Tue Dec 26, 2017 4:58 pm
Hi Arkane, that's my problem too. The detent being retracted is a manufacturing defect I think. I don't think the prongs will be able to push down the retracted detent.

Aimsurplus, where I bought it from is still on vacation so I haven't been able to talk to them.

I have multiple ARs and non of the detents are pushed down so far.
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rchen404
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Tue Dec 26, 2017 10:05 pm

Thanks e292. I unscrewed the fsp most of the way out.

The drum of the sight appears too wide for the prongs on the sight tool to make contact with the detent. Prongs only reach halfway down the width of the drum. Gonna try with my a1 tool once I get it. Would be a major pia if I had to use 2 dental picks to adjust sights

Do you know if the wide drum is the regulation AR sight?
IMG_20171226_235942-min.jpg
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e292644
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Wed Dec 27, 2017 6:13 am

You've got a tall FSP for carbine rear sight, M16A1 tool will not be able to reach the detent unless you swap out to T91 FSP.
Or, like you said use dental picks to adjust it. Once you zero it in, there's no need to touch it.
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rchen404
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Wed Dec 27, 2017 11:57 am

e292, I called Wolf who told me to call SDS Imports. They're basically saying the same thing you are. The drum is too thick for any sight tool to work. If you switch to a thinner drum, the locking detent might not engage.

so looks like I made a whole big deal about nothing. Back to using the dental picks.
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Arkane
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Wed Dec 27, 2017 2:56 pm

Try using what I use (pic below), these are more controllable than fiddling with dental picks. The reason for the taller drum on the front sight post is to allow the use of commercial carbine rear sights (since the upper comes without a rear sight). The original front sight base (like Sean sells) is designed around the M16A1 standard, which is a shorter bore to height level than the M4 uses. (which is what pretty much all the rear backup sights are built around nowadays) If you switch to the original front sight post you'll probably be able to use a regular tool, but will need to get either the carrying handle or simple rear sight Sean sells, or a Daniel Defense A1 height rear sight. I like the simple rear sight on my 91 clone, but my working rifle has the "tall drum" front sight and a Matech buis. I have yet to find a folding rear sight that is A1 height, and I'm not even sure anyone makes one.

Image

They can be had pretty cheap on ebay: https://www.ebay.com/itm/CT2224-6PC-Pre ... SwKIpWBThG
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Iamscotticus
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Wed Dec 27, 2017 3:15 pm

Are the flange diameters different between the two?
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rchen404
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Wed Dec 27, 2017 3:17 pm

Thanks Arkane. Just weird they have to resort to such a wide drum. There are non F stamped fsb that take longer posts but same same width drums.

I've read HK AR buis work but too expensive for me.

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Arkane
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Wed Dec 27, 2017 6:47 pm

Yeah the second A1 I got had the big drum, I kinda had to scratch myhead, but that's the solution they came up with instead of a taller post.
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