At this years M4C training class, I got to see Costa’s 11.5 KAC upper. Since I am a big fan of the URX II, I drooled over the possibilities of building such an upper.
A couple months passed and KAC finally allowed dealers to purchase the URX II. I immediately got on the phone to Paul at BCM and ordered some stripped BCM 11.5" barrels for my project.
Now all the pieces of the puzzle were coming together, but there was one small problem. How do I get a gas block to fit inside of the URX II?? While at the M4C class, I noticed that Costa’s GB was machined down on the sides. I thought that a bit strange as there was plenty of room on the sides of the URX II, but not on the top and bottom of the rail. Further examination revealed that they machined down the sides simply so that they could machine down the bottom corners of the GB.
So the next step was to take some LaRue Tactical GB’s and cut them in half (as they are two long for this project). We also had to flatten down the top and corners of the GB to better fit inside the URX II. Lastly, we KG coated them flat black so as not to look like anything had been done to them.
What I love about this rail is that with an 11.5" barrel, the threads of the barrel JUST clear the rail. So when you install a Suppressor (like the SF K Can), it appears that the Can integrates into the rail (as the collar of the Can almost touches the rail).
This setup, IMHO is the best SBR upper that we have ever produced. Quality through and through and built for serious use.
I recently got a URX II. I think its very cool. Obviously I haven’t beaten it to death yet but its sold and a really cool rail system with the integral front sight. Thumbs up to Knights.
That is exactly what I was looking at for my SBR project. Basically I want the rail to end right where the flash hider/ suppressor would mount so that it looks almost concentric. My barrel is actually underway to someone in VA for him to shave the gas block. Once it gets back I will study my rail options a little closer.
The LT GB was designed to cover up the pin holes from the FSB. We did not have this problem with these barrels. We were also concerned about being able to get the GB into the rail (as you basically install the rail and then install the GB).
The URX II’s are hands down the most difficult rail to install (as NO GB will fit inside of it without modification).
You just wait. You will sell all of your weapons because they will not even compare to this weapons low recoil impulse, lack of carbon residue in the receiver and little to no lubrication needed.
Then I will have Costa come in and tell you that it is the best suppressed weapon he has EVER fired.
