Has anyone installed the T91 Front Sight Assembly?

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KalashniKEV
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Wed Sep 05, 2018 3:50 pm

Is it as simple as driving out the pin, popping the old gas block off (with a press, I've heard?) and sliding the new one on and reinstalling the pin?

Is there any requirement to drill on the new block?
Is there any requirement to modify the handguards?

Thanks!


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codyphillips48
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Thu Sep 06, 2018 5:23 am

KalashniKEV wrote:
Wed Sep 05, 2018 3:50 pm
Is it as simple as driving out the pin, popping the old gas block off (with a press, I've heard?) and sliding the new one on and reinstalling the pin?

Is there any requirement to drill on the new block?
Is there any requirement to modify the handguards?

Thanks!
Yes many have installed the T91 gas block. Now with the new gas block there selling on here its easier to install but that also depends on your tooling. You'll need a press to get the old gas block off or if you dont care about it you can cut it off with a cut off wheel. With a little sanding of the journal on the barrel and in the gas block it almost slides right in. next you will need a 2.2mm drill bit and a 3mm drill bit. You can find those at ace hardware by the taps. Installing the new gas block will require you to drill a new pin hole in the barrel. then you will need a taper reamer for the pin. Me I did one myself and the 2nd one I sent to my gunsmith. It can be done The new gas block will need the gas port drilled and the pin hole drilled. Handguards will need a little sanding to make it easier to get them over the 1913 rail (at least mine did).
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changhsu08
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Thu Sep 06, 2018 1:41 pm

My gunsmith used a shop press to remove the wolf A1 gas block and installed the T91 one. That's the easy part he said.
He had some trouble drilling the gas port on the gas block and broke two drill bits; not as simple as he thought it would be. The upper now is completed and I have put around 200 rounds through, it runs good; the new gas port in the T91 gas block is smaller than the one on the wolf A1.
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akguy1985
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Thu Sep 06, 2018 11:10 pm

I'm taking mine to the gun smith in the morning.
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KalashniKEV
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Fri Sep 07, 2018 4:05 am

I've lost access to my shop (old employer), and will have to use a gunsmith on this job.

What are the 3mm and 2.2mm bits for? 2.2 on the port and 3 on the retaining pin?

Has anyone done instructions for this?
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e292644
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Fri Sep 07, 2018 4:25 am

Correct, 2.2mm on the port with 30 degree angle and 3mm on the retaining pin.
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codyphillips48
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Fri Sep 07, 2018 5:22 am

KalashniKEV wrote:
Fri Sep 07, 2018 4:05 am
I've lost access to my shop (old employer), and will have to use a gunsmith on this job.

What are the 3mm and 2.2mm bits for? 2.2 on the port and 3 on the retaining pin?

Has anyone done instructions for this?
I know on my gas block it was easy to figure it out. Both holes were started. The gas port was almost drilled threw it was like a 16th of a inch from being finished.

I don,t see installing this being any different then installing a A2 style or a AK gas block. Installing the sight is no different the then a A2, Drill smaller hole then ream out to fit the pin. Then drilling the gas block is like drilling a AK gas port. That's how my gunsmith explained it to me. That's also how I did mine on my own.
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e292644
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Fri Sep 07, 2018 6:14 am

Exactly, make sure the drill bit is 90 degree vertical, only tilt the barrel/FSB to 30 degree and drill it through carefully. Mark your drill bit depth and lock it with either drill press, lock ring, or with masking tape so you won't drill into the bottom of your barrel.
codyphillips48 wrote:
Fri Sep 07, 2018 5:22 am
I know on my gas block it was easy to figure it out. Both holes were started. The gas port was almost drilled threw it was like a 16th of a inch from being finished.

I don't see installing this being any different then installing a A2 style or a AK gas block. Installing the sight is no different the then a A2, Drill smaller hole then ream out to fit the pin. Then drilling the gas block is like drilling a AK gas port. That's how my gunsmith explained it to me. That's also how I did mine on my own.
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codyphillips48
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Fri Sep 07, 2018 8:55 am

I found drilling the barrel pin to be the hardest part of the whole thing. Keeping the gas block straight was the hardest thing for me but thats just me @onion7@ @onion7@
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KalashniKEV
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Sat Sep 08, 2018 3:35 am

OK... so now that I have the new block in hand, I see exactly what you guys are talking about:

1) Complete drilling of the port by doing 30 deg, 2.2mm on the new gas block.
2) Remove the pin and press off the old gas block.
3) Press on the new gas block.
4) In proper alignment, drill new retaining pin (3mm) and install the wider pin.
MAYBE open up the gap on the bottom of the HGs.

Is that the job?
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