SWS RS-2 Free Float tube for the AR-10
Let me begin by reminding everybody that
SWS (Superior Weapon Systems) manufactures Mil-Std-1913 rail float tubes for the AR-10 and DPMS-308. I understand from SniperX that if there was enough interest they might make some for the Bushmaster 308 as well!
I have been using one of the first ones they made on my Eagle Arms AR-10T. It is a fantastic tube and I have a review on my website here:
http://quarterbore.com/kac/ar10ffrail.html
Recently, I had seen some pics of a new version of the float tube that they were introducing but the details were fairly sparce as they worked out the patent and legal issues needed to protect their concept. I was quick to let SWS know that I was eager to obtain another of their tubes and I finally received it late last week.
This newest version of the AR-10 float tube is a better design then any AR-15 float tube I have ever seen much less the fact that this is a tube for the AR-10! Rarely does a better product come out for the AR-10 that isn't already available for the AR-15 but this may well be a good example of one...
Photos of the new tube with the hardware and tools needed
The photos above shows the new system.
Barrel Nut: The barrel nut consists of two pieces that are shown attached together with four socket head bolts. The upper portion of the barrel nut is drilled to a larger diameter then the bolts while the lower portion is drilled and tapped to allow the bolts to hold the two pieces together.
Float tube: The float tube slides over this new barrel nut design and is then attached to to barrel nut using the three socket head bolts as shown in the photo.
Tools: A unique barrel wrench, a pair of alen wrenches, and a drill bit are all that are required. You will see lower in the page that I also have a pair of Armalite AR-10 upper receiver blocks plus a drill press (but a hand drill would work fine).
Folowing are a series of pics that show how this tube is installed!
Step 1: Thread the back portion of the barrel nut onto barrel.
Step 2: Tighten with the supplied barrel nut wrench (I used a breaker bar as well with moderate force) to determine which hole lines up with gas tube hole in upper.
Step 3: Mark which whole will be aligned with gas tube hole.
Step 4: Align the hole that the gas tube needs to do through with the hole in outer barrel nut unit that is there for the gas tube.
Same as above
Step 5: Attach the two halves of the barrel nut together using supplied bolts.
Same as above
Step 6: Drill out the hole in barrel nut that has the threads so that gas tube will fit.
Hole all drilled and ready to install!
Step 7: Install barrel nut and torque down to align hole in barrel nut with gas tube hole.
Gas tube lined up!
Step 8: Install gas tube and float tube
Same as above.
Attach float tube to the barrel nut with three socket head bolts.
Same as above.
Following are a number of pics with this new tube installed on my Armalite AR-10A4 Carbine.
Update 24-Nov-2004
I posted a cut down versin of this review
on AR15.com and a rather observent member there pointed out that the rail height was changed so that this new tube does not match
Mil-Std-1913 specifications or the
Update 1 to the specs.
RE: The .367 Minimum height as on right of image above.
With this insight, I pulled some of my accessories off a couple of my AR-15 uppers with KAC FF RAS tubes on them and tried to mount them on this new RS2 float tube for the AR-10.
When I tried to mount my Tango Down and KAC grips to the new float tube they would not mount. It may be possible to grind down part of the bottom of these grips to allow them to fit but this will have the effect to weaken the grip as the material that would be removed is the material that clamps under the base of the rail for strength,
I next tried some of my ARMs accessories including my Surefire M971U weapon light with ARMS mount and ARMS #22 rings. Both of these items mounted to the new tube without any problem. I also mounted my EOTech optic to the rail and it likewise mounted without any problem. I was also able to mount KAC Pannel covers which clicked into the stops that were milled into the rails of this new tube.
In conclusion, this deviation from the Mil-Std-1913 will affect which accessories will mount to the new tube. I guess it gives me good reason to buy an ARMS #23 forward grip now and other then the grip problem I can not think of many accessories that will be problematic for the way I use my FF RAS tubes.
I am still very happy with the new tube and she is rock solid and reasonably light. She will mount all the accessories that I am likely to want to use with the tube so the changes are not major hurdles for me.
Threaded Mode
