Spanner For RRA Service Rifle Free-Float Tube?

[tpelle]

I have a Rock River Service Rifle type free float tube (the kind that fits under modified A2 handguards) on my match AR15. It's time to replace the barrel, so the free float tube has to come off. The lock ring is kind of boogered up, as the last time I did this I didn't have a proper spanner to engage the single hole in the lock ring.

I'm going to order a replacement lock ring from RRA to refit when I reassemble the rifle.

Does anyone know what kind of spanner wrench fits this thing?

[federalist22]

I'm confused.....a free float tube that fits under A2 handguards? Post a pic or two to give us some perspective.

I removed a RRA free float tube last summer from a RRA Varmint A4 using a Brownells barrel wrench to break free the barrel nut that mounts the free float tube, after first using a torch to loosen the red loctite RRA used to bind the tube to the barrel nut, and a strap wrench to break it free. Also, not only did RRA use loctite to hold the tube to the nut, but also to hold the nut to the receiver.

RRA usually uses a barrel nut that can be removed using a standard barrel nut wrench.

[tpelle]

Here's a link to RRA's site, showing the free-float tube I have.

http://www.rockriverarms.com/index.cfm?fuseaction=category.display&category_id=305

This is for NRA and CMP Service Rifle competition (a la Camp Perry), where "internal" modifications are allowed (two-stage trigger, 1/4-minute sights with hoods and lenses, free-float handguards, match barrel, etc.) but "externally" the rifle has to maintain the appearance of an as-issued rifle. Admittedly the "specs" of what's allowed have not kept pace with how the military is issuing the rifles today, no optical sights for instance, but keep in mind that you still see M1 Garands and M14/M1As on the line, so to keep them still in the running, M16s have to be of the A2 variety.

Service rifle matches are shot at 200, 300, and 600 yards with iron sights and tight slings.

[federalist22]

Ahhh....confusion cleared up. Isn't that interesting. Have you tried a Brownells barrel nut wrench? It looks like it would work.

[tpelle]

What's needed is some sort of spanner - I thought that a spanner for an M4-type collapsible stock would fit, but the one I have is a little too small. The lock nut is actually a narrow internally-threaded ring with one hole in it where the lug on the spanner would fit. I'm about 550 miles away from the rifle right now, or I would measure it.

Maybe tomorrow when I get home.

[federalist22]

Have you tried calling Rock River and ask them what tool to use? They are usually pretty helpful.