Installing Rifle Length URX Rail System on Midlength (Armalite Gas Systems)
I told Grant I would get a post out on this
Rifle Length URX with Integrated Front Sight (P/N 20547) and a commercial midlength system (which I will call the Armalite system).
We cut out the top "rib" of the URX just behind the Integrated Front Sight (IFS) these first few where to see if it would work, and the engineering print has been updated to this standard now (everyone thank coldblue)
http://img.photobucket.com/albums/v1...ngthgas001.jpg
You can see the channel runs the entire length.
A View from the top with our low profile gas block installed.
http://img.photobucket.com/albums/v1...ngthgas007.jpg
Now one issue you will find with some as blocks is that the lower "flats" will bump the lower rail
http://img.photobucket.com/albums/v1...ngthgas003.jpg
Especially with our low profile gas block, as it has extra depth so it can be taper pinned or set screwed.
Hardly the 100% solution - but grinding the sides down can give you the clearance you need
http://img.photobucket.com/albums/v1...ngthgas005.jpg
with plenty of clearance.
http://img.photobucket.com/albums/v1...ngthgas006.jpg
the Larue Gasblock has the proper taper - but it quite longer - not a problem on the 16" but can cause can issues when used on the MidLength URX and 11.5 Carbine setup.
For the carbine gas system on both 14.5 and 11.5 we milled down the flip front sight gas block on our SR16E3's
http://img.photobucket.com/albums/v1...ngthgas008.jpg
http://img.photobucket.com/albums/v1...ngthgas008.jpg
This is how the Costa gun Ver 2.1 -> are built