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1/25/2018 7:38:29 AM
Posted: 10/26/2003 1:25:26 PM EST

Looking for a little help. I bought a ff tube from RB Precision.

I have an M&A upper with no comp or hider. I think I understand the steps to punch out the front sight pins, and the gas tube. I assume everything will just slide forward/off.

I have a DPMS barrel wrench and a decent vise, so do I just leave the upper and lower together and put an action block thru the lower (don't have the action block yet)? Do I seperate the upper and lower and use something to hold the upper in the vise?

Sorry for the basic question, I just want someone to give me the detail. I'm trying to avoid make it a paper weight.

Link Posted: 10/26/2003 2:25:19 PM EST
You really need to get the Marine TM and spend some time familiarizing yourself with the maintenance procedures for the AR / M16.
Link Posted: 10/26/2003 6:07:43 PM EST
[Last Edit: 10/26/2003 6:08:50 PM EST by Fenian]
It's relatively simple...action block goes around/in the upper receiver/barrel assembly...put the receiver block with the upper in a good sized vice...it's made to fight the vise. The lower should NOT be mated with the upper...it should be sitting somewhere else on your bench! Depending on the receiver block, it might have an insert for the inside of the upper receiver...mine didn't, but it seemed to work fine. I've heard some people say to leave the bolt carrier in if you don't have the insert. Have at it with the receiver wrench...the delta ring can be a pain in the ass to work with; since I was gonna put a tube on mine, I cut it off with a dremel...the float tube has it's own barrel nut. I made two cuts 180 degrees apart, taking car NOT to mess up the barrel. The barrel will be VERY tight, depending on how much torque went on it, and how many rounds have been through it, and whether they used anti sieze compound on the threads. I've even heard of folks having to stick the upper in a freezer for a while to break it loose. Once you get the barrel off, just reverse the process using the tube's barrel nut...no need for a delta ring, spring or retainer clip. A LOT of people here don't use a torque wrench to tighten the barrel nut...if you decide not to, then just hand tighten the nut, then crank it down 'til the next hole lines up straight for the gas tube. Install the tube, and tighten it with a good strap type wrench...I didn't have one, so I wrapped a towel around it and used a big set of channel locks, being very careful not to crush the tube. Once that's tight, reinstall your front sight block/gas tube, and you're done. BTW, the sight pins may be real tight as well. Don't be afraid to give them a REAL good whack with a fair sized Ford wrench...sorry, I mean hammer hehehe. IF you're pins are tapered, make sure you bang them out the right way! It won't hurt to put some liquid wrench or Kroil on the pins, AND the barrel nut. Let 'em soak for a 1/2 hour or so before you start this project. BTW, I made my Armalite upper into a paperweight trying to do this without the receiver block. Don't even THINK about it lol. Make sure you understand what you're trying to do...it's not rocket science, but thinking about it a little before hand helps. Don't be afraid to ask more questions, either. Good Luck!
Link Posted: 10/27/2003 5:22:38 AM EST
Do not remove or install the taper pins with the upper locked in a vise. Support the offside of the FSB on something solid and go from there.
Link Posted: 10/27/2003 7:54:30 AM EST
Originally Posted By Tweak: Do not remove or install the taper pins with the upper locked in a vise. Support the offside of the FSB on something solid and go from there.
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Good point...it's a separate operation...one of those spiffy Brownell's bench blocks comes in very handy for this, but as you're gonna have to whack the pins pretty hard to get 'em started, you want the barrel well supported. Also, once you get 'em broken loose, you can use a smaller punch to get 'em the rest of the way out, but breaking them loose will require something fairly sturdy.
Link Posted: 10/27/2003 8:12:12 AM EST
No need to remove the gas tube from the FSB either. Easier to keep it together.
Link Posted: 10/27/2003 8:45:48 AM EST
Thanks for the info..
Link Posted: 10/27/2003 11:19:19 PM EST
The below hyperlink contains directions for FIRSH and it should be similiar to what you are installing... [url]http://www.triplebreakproducts.com/Olympic/how_to_install_FIRSH.htm[/url]
Link Posted: 10/29/2003 5:59:49 AM EST
This went much easier than anticipated. I was basically about a 30-45 minute job. Worst part was not having a strap clamp to tighten the FF tube, I put a scratch on the reciever tightening up the tube. Other than that a piece of cake. Thanks for everyone's help.
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