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AR15.COM
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7/7/2012 6:57:29 PM EDT
I apologize if this is a repeat thread; please link the original if so.

Recently I bought a Troy 13" Alpha rail. I followed this ((http://www.youtube.com/watch?v=mfYpR6TLEMI) link and everything has gone great so far. Now I need to put the Alpha rail onto the gun. I have the three retaining clamp screws and the little metal backing pieces for them (actually, they're similar to the screws for rail sections on my Magpul MOE foregrip).

I consider the instructions Troy ships with the Alpha rail to be complete fucking garbage. So my question is, how exactly does this rail "clamp" onto my AR-15? To get it aligned properly I will use my EOTech HWS, but I guess I just don't understand how to use the three screws and their corresponding backing pieces to install this thing.

It's been a long work week and perhaps I've gone off the deep end, but any help would be appreciated. Thank you!
7/7/2012 7:58:13 PM EDT
[#1]
Look over the instructions as to the proper placement of the mounting screws and nuts. Don't tighten em up, leave em a little loose. Your rail is gonna slide on over your mil spec barrel nut but not directly in line with your receiver, but about 5 degrees off, like at 58 minutes on a clock face. When you get the tube on, the tube will then rotate up so that it's in line with your receiver. Then tighten the 3 screws up and you're set.
7/7/2012 9:21:19 PM EDT
[#2]
I did look at the instructions, they're basically useless as far as I'm concerned. Picture 6, the last picture in the instructions, shows the little lip of the screw clamp piece pointing toward the muzzle; is this correct? It seems like some people's Alpha rail comes with the three screws and corresponding clamp pieces already on the rail, and my pieces are all separate. I guess I'm just not sure how to align the backing pieces of the screws on the rail. Honestly I don't know how this will hold the rail in place but I guess they catch on the barrel nut or something.

I was planning on going to the range with my AR tomorrow (today actually, I guess) but if I can't get the dang rail on it I'll have to take my AK and/or .22LR, lol.

Ok so I just looked at the inner surface of the Alpha rail and see grooves on each side of the holes for the three screws. I'm tired as shit and will try this tomorrow, but I think I see what needs to happen here. Still seems weird that this'll hold the rail on the gun but whatever.
7/8/2012 7:06:35 AM EDT
[#4]
Looks like the screw on the exterior of the rail tightens the clamp against the teeth of the stock barrel nut.
7/8/2012 9:09:39 AM EDT
[#5]
Ok I did end up getting it done today. Not sure why I didn't realize how it worked right away but I guess lack of sleep will do that ;-). Hahaha.

Thanks for the help guys!
7/9/2012 11:05:27 AM EDT
[#6]
Make sure you use brake cleaner on the screws and tabs, then blue loctite
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