[stargeezer]

A few weeks ago I bought a new AR upper with a free floating handguard. All was good until yesterday when I discovered the the handguard was unscrewing - the lock nut had loosened. I'm not sending it back for this simple fix. Unfortunately the wrenches I have do not include the correct nubs for snugging the nut up, and I need to buy the right wrench.

Looking at the brownells and midwayUSA webpages show a handful that will work, but the reviews on most are very bad. Most say the nubs snap off, they mar the gun, etc., they all look equally bad.

So I turn to the pros here, which one is working for you?

 

[brimic]

I use the DPMS armorer's wrench which has worked fine so far for rebarreling, installing a free float tube, and installing stocks.
I've heard of complaints with this tool with buggering up castle nuts, but I've also heard counter claims that the wrenches were used incorrectly which led to marring/damage.

Make sure you use an upper receiver vise block too if you are going to be doing wrenching on the barrel nut.

 

[stargeezer]

Thanks brimic. I have the upper block already and plastic blocks for the barrel. My bench has locations for bolting two vises on it about 16" apart. I use this setup when torquing barrel nuts. The upper receiver block goes in one and after the barrel nut is tightened up about as far as reasonable, I put the barrel blocks on the barrel and lock it in the second vise. It's over kill, but I like it to be secure as I finish the last little bit.

This free floating hand-guard is the first I've ever had that loosened. I've got two other ARs with them, but they've never backed off at all. (I wasn't sure just how they were locked on ) until this one surprised me the other day)