UTG Quad Rail Install

[Slide Rule]

Hello everyone. My dad and I are building our first AR15 from a kit. Trigger group installed, mag release (Bullet button), safety, barrel, stock and buffer installed no problem.
As part of the kit, we received a UTG Pro Quad Rail, U416F, Model 4/15. We're trying to mount this thing to the barrel nut, and simply put, the instructions suck.


Anybody out there installed one of these before? Can you give me some pointers? I've looked on youtube trying to find some vids on how to get this thing installed and aligned up correctly, but haven't found anything pertaining to the model I have. Any help would be appreciated. Thanks.
Slide Rule

[FMJBT]

Any pics or links to the specific model? Google search turns up several different flavors of UTG forend.

[autoduel]

IS it this?

http://www.pyramydair.com/s/a/UTG_PRO_Model_4_15_Carbine_Length_Quad_Rail_System_Black/4676?gclid=CP3RidyD1rgCFWYV7Aod2QcA7Q

The non-free float handguard looks like it's indexed to the delta ring.
The installation pic shows it snapping on just any other handguard by pulling back the delta ring. Then you put in the screws.

[Slide Rule]

No, it does not come in two pieces like the one in the link shows. It is a UTG Pro, U416F, Model 4/15. I looked and there is information for the U416S, but that doesn't help me. I was hoping that someone would have experience with this. The quad rail is one complete piece. It attaches to the barrel nut with screws. What I'm in the dark about is what are the 'alignment pins' for. The instructions don't go into the purpose of them, and where I use the screws on the barrel nut to attach the rail. There are a bunch of holes on the barrel nut that the screws could go in. Also, there are 6 screws, 4 the same length, and two longer. The instructions don't go into the purpose of the varying screw lengths. Sorry for the odd question, it's got me stumped though.

[FMJBT]

Pretty sure you are describing the newer USA made free float rails (MTU006). I have one of these on a 16" mid length. The screws go in through the bac of the barrel nut and into the threaded holes in the mounting flange of the forend. The 2 longer screws are for if you use the anti rotation tabs, the extra length allows them to pass through both the anti rotation tabs and the barrel nut before threading into the mounting flange. If you dont use the anti rotation tabs, the shorter screws will be used in those holes.

As far as alignment pins, they will align themselves into the proper holes in the barrel nut as long as the barel nut and forend all line up with the upper receiver. The holes in the barrel nut that dont have alignment pins in them are the ones that the screws pass through. Should be the upper hole nearest the top rail on either side, and the 2nd hole down from that on either side:

[Slide Rule]

I think you confirmed my thoughts FMJBT, thank you. One more question, all the alignment pins are for are to line up the rail to the barrel nut, right? Does screwing them in or out with a flathead screwdriver do anything? Thank you again, I appreciate it.
Regards
Slide Rule

[FMJBT]

I think you confirmed my thoughts FMJBT, thank you. One more question, all the alignment pins are for are to line up the rail to the barrel nut, right? Does screwing them in or out with a flathead screwdriver do anything? Thank you again, I appreciate it.
Regards
Slide Rule

Yep, pins are just there to help align the rail to the barrel nut, no need to mess with them at all. Just make sure whe you tighten down the 4 screws that hold the rail in place, tighten them just a little at a time in an alternating sequence to evenly distribute the force as you screw it in place. Kind of like lug nuts or cylinder head bolts on a car. As you snug everything up, make sure to periodically check to make sure the alignment of the top rail doesn't shift. Shouldn't be any problems, but it's always a good idea to take your time and double check things when installing alignment critical parts. When torquing down the top screw on the ejection port side, make sure to hold the anti rotation tab in place against the receiver, as the torque from the screw head can rotate it out of position. The UTG is actually one of the easier forends I've had to install. Extremely well designed and very solid but lightweight as well. One of the few UTG parts I have absolutely no reservations with using or reccomending to others.