Gents.  It's been a long time since I have done an A2 rear sight install.  I'm working on a JSOC Model 727 modified project, and after Cerakoting my receivers, I'm looking at the upper and drawing a blank on the complicated rear sight assembly install.  I think I blocked out the last experience, because it went so bad...something about small ball bearings and lots of profanity...

Anyway, I've used my google-fu, youtube-fu, and Arfcom search feature, with nothing found on any type of tutorial how to do it.

I'm looking at my small parts, and realizing that I need help badly.

While sourcing the missing parts from a kit I ordered, I learned that the forward assist roll pin and the roll pin that retains the threaded tower for elevation of the A2 rear sight protective body are the same part.

I dis assembled an A2 rear sight only once...
hope these pics can help you

use a glob of grease to hold ur ball bearings in place during re assembly.  That severly cuts down on the profanity!

Brownells A2 sight installation video

Thanks gents!  

post pics when u get it together!

I ordered the assembly from Midway, and it's a DPMS kit.

It was missing the windage screw, the retaining roll pin, and large tension spring that goes under the sight base from inside the upper.  I still need one of those.

This is a "Retro-ish" project intended to duplicate one of the highly modified Colt 727's I saw with a certain unit.  The one I saw had what looked like one of the Bushmaster-marketed VMATCH rifle-length free-float tubes, with the knurled surface in the middle, with a FSB cut pocket.

It had a reflex suppressor half-concealed under the float tube like an MP5SD, with small Weaver scope rail sections appropriately drilled and tapped into the rail for his Surefire 6P, a PAQ-4C, and a Vertical Fore Grip.  

The stock had the slip-over recoil pad zip-tied to it, with the Delta cheek piece.

Lone Star pistol grip

ARMS optic mount, with an Aimpoint

The whole blaster was bow-flaged.  One of the coolest Colt Commando variants I've ever seen.

I have everything except the Delta cheek piece, ARMS mount, and Aimpoint.  I'm using Cerakote for the simulated bow-flage, since it doesn't wear off like bow-flage, but has the same extreme matte texture when mized to a certain ratio of hardener to ceramic color.

Is there one for disassembly? My elevation knob will not budge at all. I've got everything but can't find a way to loosen the whole rear sight assembly so I can pull it out. I need to get the elevation discs out to inpect them.

I bet you need to turn the elevation disc indexing set screw in to be able to turn your elevation wheel.  You have to back it out to slip the disk so that the scale can be correctly indexed, as shown in the video.  If you leave it turned out, it will be up in the hole that accesses it in the receiver, preventing tunring of the elevation wheel.

You need a small allen wrench to turn that little screw.

P.S.:  Does anyone have a source on the tension spring that goes in through the inside of the receiver???   It's one of the many parts not included in the DPMS kit I ordered from Midway.

http://postimage.org/image/z0c8t7kb9/



It's part #5 in the above diagram.