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Posted: 11/23/2010 4:50:31 AM EDT
I got this type of factory aluminum free-float hanguard on my inbound DPMS LR-308.. (notice the gas-block is smaller than the HG) 
http://accessoryarms.com/forums/DPMSA3.jpg What type of tool would I need to remove it?? (if any)?? I was thinking of uprading to the simple DPMS Free-Float Quad. http://www.dpmsinc.com/store/products/images/?id=1843 Is this upgrade for my situation just simple..?? like unscrew one and screw on the other?? Sorry I am a 'Noob' to AR's. Al |
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goldeyeslayer.. that is a good post... covers my trigger questions and some other stuff... BUT...
it does NOT cover my current type of Aluminum Free Float that I have on this.. (as shown in the picture) I don't see the barrel nut (its under the current free-float I guess), I don't have an A2 type gas-block/sight in the way either.. Does anyone have a DPMS upper with factory aluminum free-float (like mine) with the same type of gas-block... that can help me out??? Al |
| Chances are you will have to replace the barrel nut as most are specific to the tube. You might be able to get that tube over the gas block, but not the barrel nut. Put upper in vice block, remove gas block/gas tube and then the float tube. It looks like that float tube acts as a barrel nut. do you have a pic from the back of the tube? |
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goldeneyeslayer..
No pics yet.. however upon treading the internet.. I read the Aluminum FF I have is and integrated to the barrel nut/delta-ring combo.. what I found was.. Remove the gas-block and tubing from the upper.. Someone said some heat (heat gun) and a 'strap-wrench (nylon type)' and some umpff may work to remove the FF and barrelnut combo.. Then install the new barrel-nut, and install the gas tube and the gas block,.. then 'thead on' the new FFor Quad. Does this sound right?? Al |
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When I assembled mine I did the following.
1) Install barrel w/barrel nut that came with the quad rail. Actually the DPMS quad rail comes with a barrel nut and a lock ring. 2) Screw on quad rail and test fit the gas tube/gas block. What I mean by this is to adjust the quad rail so that the gas block is just underneath the quad rail by maybe 1/8 to 1/4 inch. 3) Use lock ring to lock quad rail into the correct position. I use blue locktite on quad rail threads and lockring. 4) Install gas tube/gas block assembly. |
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The aluminum handguard tube on an AP4 has 2 pieces. If you look very carefully, you will see a seam about 1.5" from the aft end. The aft part is the "nut" and the forward part screws onto the nut. Heat the seam area to loosen any locktite, then use a strap wrench to remove the front part of the tube. Once the front part is off, you can use a wrench to engage the holes in the "nut".
You'll need this wrench Barrel nut wrench And you'll need this to hold the receiver Receiver vise claw |
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I removed the same float tube (except mine is rifle length) from my LR308 to blast the barrel and make it a matte finish. Here's what I did.
First, bought this $30 strap wrench from Home Depot: HD strap wrench link Removed bolt/carrier/charging handle from upper. Removed gas block/gas tube. I left the gas tube in the block. Clamped upper sideways in my vise between two pieces of hardwood. One piece protected the rail and the other piece sat between the two takedown pin bosses and protected the bottom of the upper. Heated threaded area briefly with propane torch. Heated it too hot to touch, but not too hot to melt the nylon strap of the wrench. Put wrench on tube where the flutes start. Started cranking and the tube part came loose from the nut part. Reheated nut part and then loosened that with the strap wrench. Assembly was reverse of disassembly. |
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One shouldn't have to make the tube part on the DPMS aluminum non slotted forearm that tight. I just crank mine up hand tight and never have had a problem.
I don't see having to heat it up with a torch to get the tube portion off the barrel nut. DPMS has the nut and tube mated so closely it's hard to see the line between them at times. It does appear you may have to remove your gas block in order to get the tube off and that is no big deal. |
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Quoted:
Reheated nut part and then loosened that with the strap wrench. Assembly was reverse of disassembly. Um.. how did you remove the NUT part with the gas tube still running thru it.?? You gotta take off the gas tube don't you to remove the barrel nut?? Or was the barrel nut the same?? and you just reused it for the new Quad / Rail?? Be great if you don't have to remove the barrel nut and such.. indexing may be a PITA for a noob like me.. Scott_S.. let me know please I am dying to jump on this project when I get 'Jersey' (new rifles name) 
Al |
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Quoted:
Quoted:
Reheated nut part and then loosened that with the strap wrench. Assembly was reverse of disassembly. Um.. how did you remove the NUT part with the gas tube still running thru it.?? You gotta take off the gas tube don't you to remove the barrel nut?? Or was the barrel nut the same?? and you just reused it for the new Quad / Rail?? Be great if you don't have to remove the barrel nut and such.. indexing may be a PITA for a noob like me.. Scott_S.. let me know please I am dying to jump on this project when I get 'Jersey' (new rifles name)
By the looks of your DPMS forearm you have to take the gas block off to get the tube off so gas tube will come off with it. From the sounds of it I think you better enlist someone that knows how to do this stuff and I mean do it well and right. Re torquing the gas nut the second time is different then from the first time it's been torqued up. Either that or you had better read up on all this thoroughly. Al |
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I read up on the timing of the bbl nut thats why I was asking on how you did yours without removing the gas-tube from the bbl nut (it would twist it up)..
I know I need to make the bbl nut about 30-70 lbs and re-time it for the gas tube to pass thru.. Overall that was the reason for considering the DMPS FF Quad.. same mfg and parts should go on about the same.. So I 'break apart' about 1 1/2" IN from the AFT part of the handguard.. (with strap wrench).. then use DPMS barrel wrench tool to remove bbl nut (if needed) and then reverse assembly.. overall not to hard.. which direction should I punch the gas-block retainer PIN out??? (ejection side or other side)?? what size punch?? 1/8" or ?? Al |
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Quoted:
I think you're making this way harder than it has to be. Indexing the nut is not hard at all......and I'm 99% sure the one you have will not work. goldeye.. I plan on doing this in a month or so (or after new years)... just want to get as much info as possible.. Its ok.. most $150+ quads come with a new bbl nut and such.. (including the DPMS FF Quad I was looking at).. I have taken apart a few Saiga AK variants and grinded/hacked on them (and all was well) I do have some MOD experiance.. I will know more when I get this 'in-hand'. I was going to farm it out for trigger work.. but installing an aftermarket (aka JP, etc..) don't seem too daunting.. 1 'smith' quoted me $60 to do a trigger change.. I dunno.. still up in the air on that also.. Al |
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Ok... got it figured out.. after watching a Midway video on YouTube.
need a DPMS CLAW and vise to hold receiver.. need a DPMS barrel wrench.. need a 'strap' wrench.. need a 1/16" roll-pin punch.. 1) mount in DPMS claw or similar item to hold upper assy. 2) try to break free the current rail at 1 - 1 1/2" mark on the current tube with strap wrench. (and possible heat gun) 3) if it breaks free see if it will clear the current low-profile gas block 4) if not remove gas-block and tube with the 1/16" punch and the set screws UNDER the gas block. 5) remove barrel nut using DPMS barrel wrench 6) install new barrel nut for the new Quad raill.. align holes for gas-tube 7) install gas-tube and gas-block back on unit. 8) screw on NEW Quad rail. done.. Does this sound about right?? Al |
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