Two Piece Quad Rail for M-4 AR-15

[loose noose]

Has anyone ever heard of the above quad rail designed for a M-4 flat top AR-15, so that the front sight/gas block doesn't have to be removed, just loosened and the quad rail will clamp on, in place of the standard forearm, and then the front sight/gas block replaced. The guy I do gunsmithing for insisted I do such an operation on a Stag Arms, AR-15 M-4 for a customer.

I tried to explain to him the front sight would have to be removed along with the flash suppressor, and a new gas block would have to be installed, as well as the appropriate barrel nut. I'm totally unaware of a 2 piece quad rail on the market, as I built quite a few free floating AR-15's with the quad rail. However I could be wrong it's happened before.

I'm looking for some feedback in this matter, as he is adamant that it can be done. Note he wants to have me to install a scope, in front of the rear sight, and he insists I leave the rear sight (GM Gear) in place. Any help in this matter will be greatly appreciated.

 

[Sam1911]

Midwest Industries makes a number of two-piece quad rails that basically drop in.

https://www.midwestindustriesinc.com/index.cfm?fuseaction=category.display&category_ID=149

Is that the sort of thing he's talking about?

 

[Sam1911]

And I'm not sure what you mean by "loosening" the front sight block/gas block. It's either pinned in place, or it's un-pinned and off, right?

With a drop-in set you just snap it in place in the original hand-guard retainers and go.

 

[Malamute]

There are simple rails to attach stuff to that are simply replacements for the handguard, and theres free float units that only attach to the barrel nut. Many require removing the sight/gas block, and some that dont. Some only require the delta ring to be cut off. The Daniel Defense Omega is one of the free float type that dont require any modification to the gun.

By "scope", do you mean a regular type rifle scope, or a red dot or other modern optical sight? Its not unusual to leave the rear iron in place on some modern optical gunsights. Many have fold down backup sights left in place, but a google search showed an A-2 type rear sight. May not work with a regular style rifle scope but is probably fine with many modern sights.

 

[loose noose]

Sam1911, the one he had was an aluminum one piece, in addition he had a cheap set of aluminum B-Square medium mounts he wanted the scope mounted in front of the removable rear sight which is a cheap GM Gear rear sight adjustable for windage only. The front sight is definitely pinned on.

I tried to explain that using that set up with a long scope (4X16 power) the front sight would definitely be in the way. Further I doubt he would be willing to pay $129.+ for the proper quad rail. The one he had I believe was listed at $49.95.

 

[Malamute]

With those added details, you are probably correct. A regular scope isnt going to be compatible with an iron rear sight in that way, and he likely isnt going to want to pay real money for top quality parts. The Daniel Defense Omega is about $250-$275 or so. I believe Midwest and others also make two piece free float rails, but most require some modification to the gun, if only the delta ring cut off.

Sadly, people sometimes choose parts based on low price, but dont understand why they dont work quite the same as more expensive parts (or require more work to install them).

The front sight may not be a problem. At about 4x and up, the front isnt very noticeable. At lower powers they can be fuzzy looking and noticeable.