Rail too close to the receiver - Page 1

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[ARCHIVED THREAD] - Rail too close to the receiver

Posted: 1/10/2018 2:05:23 AM EDT

I just finished installing an ALG EMR V2 rail and barrel nut and the rail is just a little bit too close to the lower receiver and hits the metal around the takedown pin pivot point. It's only a couple hundredths of an inch off but no way to get the holes to line up to push the pin through. If I move the rail away enough for everything to fit the screw holes no longer line up.

Maybe the metal around my pivot point is a hair out of spec or maybe the rail is just a bit too long. In either case, I don't really have the tools or ability to machine away metal without totally buggering up the receiver or rail. Maybe ALG can fix it and I'll contact them, but I was curious if anyone else ever ran into a similar issue and how you solved it.

I did follow the directions for installing the barrel nut and no reason to think I did that wrong.

Posted: 1/10/2018 2:10:35 AM EDT

[#1]

Picture?....ALG is g2g, who made your lower?

Posted: 1/10/2018 2:26:12 AM EDT

[#2]

Would not take much time with a hand file to make a small amount of clearance at the pivot points, then coat with Aluminum Black to cover it back up.

What brand is the upper and lower?

Posted: 1/10/2018 2:28:30 AM EDT

[#3]

Not sure how clear it is, but the rail and receive touch. In this position I cannot install the screws. If I disassemble the upper and lower and properly install the rail and screws I can't reassemble. Rifle is from a local company called VDC Armory.

Posted: 1/10/2018 2:31:27 AM EDT

[#4]

Looking at that rail, I would probably pick up a small flat hand file and relieve the back of the rail tube to give you about a mm of clearance, it will not affect the performance of the rail what so ever and again, you can use aluminum black to match it back up in color, you can get a small hand file at the hardware store for a couple of bucks and it would only take a few minutes of filing and then check the fit.

Posted: 1/10/2018 2:43:59 AM EDT

[#5]

do you have another lower to test fit?

Posted: 1/10/2018 2:48:16 AM EDT

[#6]

plastic lower?

Posted: 1/10/2018 2:50:54 AM EDT

[#7]

Thanks for the tips on aluminum black. Didn't know about that. Might be the fix I need along with some filing work.

Quote History

Quoted:
do you have another lower to test fit?

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I don't have another lower. Well, I have an AR10 but I don't think the AR15 upper would fit the AR10 lower. Pretty sure the AR10 lower is longer.

Posted: 1/10/2018 2:52:03 AM EDT

[#8]

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Quoted:
plastic lower?

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No. Not sure if it's billet or forged though. Looks a bit like billet but I don't have enough experience to say for sure.

Posted: 1/10/2018 2:58:53 AM EDT

[#9]

Quote History

Quoted:
Looking at that rail, I would probably pick up a small flat hand file and relieve the back of the rail tube to give you about a mm of clearance, it will not affect the performance of the rail what so ever and again, you can use aluminum black to match it back up in color, you can get a small hand file at the hardware store for a couple of bucks and it would only take a few minutes of filing and then check the fit.

View Quote

Yep, I would do exactly this and move on with life

Posted: 1/10/2018 12:31:59 PM EDT

[#10]

Do you have at least the black shim under the barrel nut?

Gary

Posted: 1/10/2018 12:34:37 PM EDT

[#11]

Mine is the same...they tell you in the instructions that you must have at least the black shim in. It keeps the hand guard just far enough off to clear the lower.

Posted: 1/10/2018 1:06:55 PM EDT

[#12]

Quote History

Quoted:
Do you have at least the black shim under the barrel nut?

Gary

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For proper torque I had to use the two blue shims so yes, shims are in place.

Posted: 1/15/2018 11:00:18 AM EDT

[#13]

FWIW, I have no compunction about removing metal from various AR-15 parts, using a file/grinder/cutoff-wheel. I understand some people want their hand-built rifles to be picture perfect, but to me the AR-15 is at heart a military rifle intended to be knocked around in normal use. Along these lines, take a look at the finish wear US Army rifles typically show after a year or so of hard use in combat zones. To some eyes, they look beautiful, a mechanical version of the red badge of courage. - CW

Posted: 1/15/2018 4:52:05 PM EDT

[#14]

I had similar issues with my ALG EMR V2. Really close in that spot and the barrel nut came very close to bottoming out on the top edge of the receiver even with the correct shims for timing. Also, the barrel nut bound up against the dust cover retaining pin, bending the pin, scarring the barrel nut, and scarring the boss that holds the pin. I ended up replacing the dust cover with a Strike Industries Ultimate Dust Cover since it doesn't use a pin. I have nothing against ALG. A lot of people like them. But it did take quite a bit more work to install, adjust, and fix things than with other free float handguards I've used.

Posted: 1/15/2018 7:48:13 PM EDT

[#15]

I checked with ALG. They said when things work they work well but when they don't it's a pain - yeah. So their solution was to use different shims. No other shim combination worked with proper torque. I originally used two blue shims to get the pre-torque band in the right place. I found that the black and green were close but required more torque to line up the barrel nut. Hopefully it wasn't too much. Didn't feel excessive.

With the different shims the rail no longer touches the front takedown pivot but it's really close. I might end up taking a bit off just to make a bit cleaner. I'd also like to go back the proper shims but I guess if the barrel nut is on maybe no reason to mess with it any more.

Posted: 1/15/2018 7:52:41 PM EDT

[#16]

I used a ALG rail on my wifes build and had to use multiple shims to make it work.

Posted: 2/1/2018 1:35:57 AM EDT

[#17]

So I wasn't real happy with using the wrong shims and maybe too much torque so I went back to the proper shims and modified the rail slightly by machining off about 1/16" from the bottom. Works fine now and hardly noticeable.

Re-blackened with aluminum black. Worked okay.

Posted: 2/1/2018 2:09:29 AM EDT

[#18]

Actually it looks good.

Posted: 2/1/2018 2:49:34 AM EDT

[#19]

Fixed.

Posted: 2/1/2018 4:45:13 PM EDT

[#20]

Quote History

Quoted:
Actually it looks good.

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Posted: 2/5/2018 1:44:15 AM EDT

[#21]

Nice cut job.

That is a forged lower btw.

Posted: 2/5/2018 8:59:38 AM EDT

[#22]

Different lower, different rail - but I did what others suggested. I small amount of metal removed with some sandpaper (aluminum cruds up a file pretty quick and has to be cleaned out or the file is shot) and then I touched up with some flat black spray paint. It's on the bottom, no one can even see it.

Posted: 2/5/2018 9:40:39 AM EDT

[#23]

Did you follow the instructions for picking the correct shim rings? You have to follow them to a "T" or the holes will NOT line up.

Posted: 2/5/2018 6:24:59 PM EDT

[#24]

Quote History

Quoted:
Did you follow the instructions for picking the correct shim rings? You have to follow them to a "T" or the holes will NOT line up.

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His last pic shows the screws in place so I reckon he got it right. Nice job phdog.

Posted: 2/5/2018 6:36:32 PM EDT

[#25]

Quote History

Quoted:
Did you follow the instructions for picking the correct shim rings? You have to follow them to a "T" or the holes will NOT line up.

View Quote

I did. ALG's suggested fix was to use different shims. I thought that was odd so did this instead and went back to the proper shims.

Posted: 2/20/2018 2:16:18 AM EDT

[#26]

Quote History

Quoted:
Actually it looks good.

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[ARCHIVED THREAD] - Rail too close to the receiver

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