AR-15 free float handguard change: what's needed and how?

[Dafapa]

I'm planning to swap out a free float tube hand guard on a rock river to a UTG free float quad rail hand guard (carbine length). I've done some poking around online but haven't seen a straight forward explanation of the process yet. My understanding is that I will need the following:
Vise
AR upper receiver block
bench block
barrel nut wrench

I know I need to remove the flash hider and gas block first, but I'm unclear on what comes next. It seems that free float hand guard retention systems vary, and some may be loctited in place. I think you have to remove the barrel nut in the swapping process. If that is the case, do you need to check the head space afterwards if you inadvertently disturb the barrel after removing the nut?

[308]

Use the upper receiver block to hold things still in the vice.
Remove the handguards of course.
Remove the FH
Drive out the tapered pins holding the FSB/GB (do this on the bench before you vice it up)
Grease the bbl and slide the FSB/GB off (the grease keeps the finish from getting scratched)
Use the bbl nut wrench to remove the delta ring

Now the bbl will slide in and out of the upper...just thought you might like to know that.

Now you slide the freefloat tube BBL nut over the bbl, screw it onto the upper and index the gas tube hole to match the gas tube hole in the receiver.

Screw the frefloat tube on and torque it down. Sometimes there are slots on the tube that you want to line up at 12 3 6 9 just so it looks nice. A bit of blue loctite will help hold the tube in place if you don't want to tighten it down too much, bu just use a dab...its all you need

Put the FSB back on and make sure the gas tube doesnt bind...you can test this before screwing the tube on FWIW

Drive the tapered pins back in from the correct side and you are ready to go.

I think that's it...I've done it many times...piece of cake.

[Schuetzenman]

.308 has done a good job of explaining. I can only add that there are a couple of different systems for attaching a free float handguard. I have a match rifle with a round FF handguard. The barrel nut is integral to the design of the FF handguards, in other words it's not separate from the handguard or said another way the handguard is the barrel nut.

Others use a separate barrel nut that you put on to replace the bicycle sprocket like military barrel nuts. Lastly some ff handguards like the Daniel Defense Omega system use the stock military barrel nut for a mounting point.

On do you have to check headspace if you pull the barrel out of the receiver the answer is NO. The barrel extension on the back of the barrel stays attached. That is the part that has the slots for the bolt lugs to pass through and then turn to lock into. Bet you didn't know that part of the barrel is actually a separate piece. It can be removed and replaced if need be. Brownell's and some other places sell the the special lug type wrench to take it off.

[Dafapa]

Thanks for the information. It sounds like I need to call up RR and find out exactly what retention system is used for the factory FF tube so I know how to get it off.

This is getting off the original topic, but what other tools would be required to do head spacing if I wanted to install a new barrel sometime? This little project is going to require a decent investment in tools, and I'm considering just biting the bullet and getting all the rest of the tools I would need to assemble an AR from the ground up. I think you can do the lower with basic tools (probably need a set of punches). I think if you have the tools to do the head spacing and replace the hand guards you should then be able to build an AR from the ground up (or am I missing something?).

[308]

Well, it is my understanding that no headspacing is required when replacing a bbl on an AR.

FWIW, you have been around here a long time and considered trustworthy. That being said, I would let you borrow my tools if you would agree to cover the shipping costs.

Let me know.

[Dafapa]

I got up with my the manufacturer and the hand guard is loctited in place with blue loctite. So it appears I'm going to need a heat gun and some luck.

308, thanks for the offer, but I've decided to just bite the bullet and buy since I want to start making an entire AR-15 tool kit to build AR-15s.

BTW, anyone have any advise on punch sets for AR-15s? I know I need at least one roll pin punch for the gas tube pin for this adventure. I'd like to go ahead and get a pin punch set, roll pin punch set, and roll pin starter set. I was thinking of just picking up the sets available at Brownells.

[Schuetzenman]

Check Brownell's, they sell tool sets dedicated to AR use for punches and other tools you might need. Blue loctite is almost the weakest variety that is available. On screws bigger than 8 size it can be broken free with no issues. I doubt you'll need a heat gun.

[Dafapa]

Check Brownell's, they sell tool sets dedicated to AR use for punches and other tools you might need. Blue loctite is almost the weakest variety that is available. On screws bigger than 8 size it can be broken free with no issues. I doubt you'll need a heat gun.

That's a relief on the loctite. I'd heard some scary things from a friend about failing to remove loctited parts even after heating with a torch, though I don't think he specified blue or red loctite.

I see brownells and midway sells some AR punch sets, but for the price its about another 20 bucks to get an entire punch set. I'm wondering if its worth the extra to just get a set of regular punches, roll pin punches, and roll pin starters. Probably run me about another 60 bucks total, but as many times as I needed a pin and even roll pin punch for something gun related I'm thinking it might be worth it. Can anyone tell me what size roll pin punch the gas tube pin is? One thing I'm worried about is buying a punch set and not having the one size I need...