Hi guys.

I just bought a YHM free float and was wondering how you tightened the locking ring between the reciever and the forearm.

I know that YHM sells a tool for this but I would rather not pay for it.

I also read that you can tighten it with a flat-head screwdriver and a hammer, But that sounds a bit brutal to me.

Any suggestions.

www.ar15.com/forums/topic.html?b=3&f=4&t=226782

Yeah,

I know, that's where I read about the hammer / screwdriver technique.  Still sounds a bit shady.

Just hand tighten, use a little blue loctite, wrap your screw driver tip with something to protect your finish (duct tape etc.), and just gently smak the screw driver.  You could try a C clamp but I think that is more likely to hurt your finish than the screw driver.  Or just get the wrench.

Save the hammer & screwdriver for conduit nuts in j-boxes.

Buy the wrench.  No substutite for the right tool.  I have never had a loose YHM using the tool, and the following technique - without loctite.

Install & time the barrel nut.  The YHM nut has a long bore for the gas tube, so alighment is more critical.  Make sure you check it with a bolt carrier installed.  With the tube slid all the way into the bolt carrier, it should center on the barrel.

Apply a little anti-sieze or your favorite gun oil to the tube threads.

If you have a flat top upper, you need to set the pitch distance of the tube.  Start by screwing the jam nut all the way to the rear of the barrel nut.  Spin the tube on to within 1 turn of the jam nut.  Now, using your calipers or a scale, set the spacing of the cross slots to match the pitch of the upper.  This way mil std 1913 accessories will fit across the reciever & handguard without a problem.   You can skip this if you have an A1 / A2 upper.

Timing the tube.  
If you have an A1 / A2 upper, adjust the tube to match your upper.  You can visiually align the tube on the bottom, by using a parallel on the bottom of the upper, and sighting across the bottom rail on the handguard.  Snug up the jam nut with your fingers.

If you have a flat top upper, you can time the tube by clamping a carry handle or mount riser across the two parts.  Once the rails are in line, tighten the jam nut snug

Tightening the jam nut.
Once you have the adjustment where you want it, use the YHM wrench to tighten the nut as much as possible before placing the receiver in the vise blocks.  On flat tops, if you can leave the carry handle or riser block attached for this, do so.

With the receiver clamped securely in the blocks, TIGHTEN the jam nut.  Wrap a rag around the YHM wrench, use both hands, and go after it.  The wrench is too short to do any damage with your hands.  Avoid using any kind of "cheater" on it - you can still get to 60 ft/lbs with your bare hands.  

If you have trouble with the tube moving while tightening, you can hold counter-torque with a strap wrench.  Make sure you wrap the strap near the jam nut, so that the barrel nut supports the tube where you are gripping it.   A strip of leather & a chain type vise-grip also works well for this.


Good Luck


Lem

+1 for using the right tools for the job.



if not, hack away