TerryF Posted October 29, 2013 Report Share Posted October 29, 2013 I have a DPMS LR-308B. I love the accuracy and dependability. I replaced the A2 buttstock with a Magpul ACS and topped it with a good 1-4 x scope. I like to run a bipod with a rifle this heavy, but when I use the short stock forend, it leaves no space for my hand. I purchased a new longer free-float handguard off GunBroker that is purported to work with the LR-308. I have a low-profile gas block ordered from DPMS to fit under the forend. I have removed the gas block, gas tube and most of the stock free-float forend. I was able to get the larger piece of the forend unscrewed by using a heat gun to break it loose. The part I have left is about 1-1/2 inches long with the same diameter and external finish as the rest of the hardguard and has a zillion gas tube holes in it. I believe this has to come off also, because my new tube has a part that has the same number of gas tube holes and the threads do not match. My issue is that the remaining forend/barrel nut thing is refusing to come loose. I can't budge it with a strap wrench and I can see no other way to get hold of it. No flats or notches or anything. Can somebody give me a hint or something? Terry Quote Link to comment Share on other sites More sharing options...
98Z5V Posted October 29, 2013 Report Share Posted October 29, 2013 (edited) That's the barrel nut, brother. You need a vise, upper receiver vise block, and a barrel nut wrench that will fit that barrel nut. Anything else will cause you to pull your hair out, if you haven't done that already... EDIT - DPMS probably loc-tited that sucker on there, too. Mentally prepare yourself for that. Edited October 29, 2013 by 98Z5V Quote Link to comment Share on other sites More sharing options...
Matt.Cross Posted October 29, 2013 Report Share Posted October 29, 2013 That's the barrel nut, brother. You need a vise, upper receiver vise block, and a barrel nut wrench that will fit that barrel nut. Anything else will cause you to pull your hair out, if you haven't done that already... EDIT - DPMS probably loc-tited that sucker on there, too. Mentally prepare yourself for that. Tom is right on the money here, and is especially correct about the loc-tite. Put the heat gun on that barrel nut when you get it all vised up, and don't let up for a couple minutes or so, and then put the barrel nut wrench on that sucker and go to town. Quote Link to comment Share on other sites More sharing options...
TerryF Posted October 30, 2013 Author Report Share Posted October 30, 2013 Thanks guys, I really appreciate the quick response. I have a DPMS barrel nut wrench, however I may have the wrong wrench, as I can see no way for the wrench to attach. No flats, notches or holes except for the gas tube clearance. You are probably right about the Loc-Tite, as the forward part of the handguard had white gunk in the threads. Any idea on the torque spec? The Brownells video says 30-80 ft-lbs for the little AR-15s. Terry Quote Link to comment Share on other sites More sharing options...
98Z5V Posted October 30, 2013 Report Share Posted October 30, 2013 (edited) 30-80 is correct. Go 30 three times (tight, loose, repeat) to set everything. Go 30 again, line it up with the next gas tube hole, and it's done. That won't be over 80. If you take it to 30 that final time, and you're perfect on a gas tube hole, you're done. No need to go any further. Now, in addition to probably loc-tite on the barrel nut that's on there now, it's probably tight as hell, too - more towards the 80 in the range. You'll have to fight it, I'm positive. Post a pic of that barrel nut wrench that you've got - let's see what it is. Edited October 30, 2013 by 98Z5V Quote Link to comment Share on other sites More sharing options...
FaRKle! Posted October 30, 2013 Report Share Posted October 30, 2013 (edited) Loc-tite on a barrel nut? WTF? Not having faith that their armorers can torque to correct specs and thus have to rely on loc-tite is a baaaaaaaaaad sign... Grab yourself a KAC Barrel Extension Wrench to make holding onto the upper easier (yes it's AR-10 and SR-25 barrel compatible). Brownells has a similar tool, but I don't think it's as functional since it requires you put the barrel nut wrench in a vise. Edited October 30, 2013 by FaRKle! Quote Link to comment Share on other sites More sharing options...
98Z5V Posted October 30, 2013 Report Share Posted October 30, 2013 Seen it happen, man. Loc-tite on barrel nuts, receiver extensions-into-lowers, flash suppressors... You never know where you'll find it on some complete rifles... Quote Link to comment Share on other sites More sharing options...
FaRKle! Posted October 30, 2013 Report Share Posted October 30, 2013 (edited) Which DPMS barrel nut wrench do you have? You should have this one. Once you attach a breaker bar to it you may need to hit the end of the breaker bar with a rubber mallet till it loosens the barrel nut enough for you to finish it by hand. A propane torch will also work to heat up the barrel nut hot enough (250C for loc-tite) to weaken the loc-tite if you don't have a powerful enough heat gun. Please don't use loc-tite when you re-install the barrel nut either! Edited October 30, 2013 by FaRKle! Quote Link to comment Share on other sites More sharing options...
Matt.Cross Posted October 30, 2013 Report Share Posted October 30, 2013 I have a DPMS barrel nut wrench, however I may have the wrong wrench, as I can see no way for the wrench to attach. No flats, notches or holes except for the gas tube clearance. Terry If it's the correct wrench, it will have several small protrusions that fit into the gas tube holes in the barrel nut. Don't go buying that wrench either, several of us have one we will ship around for goodwill's sake, you're certainly welcome to mine. Quote Link to comment Share on other sites More sharing options...
sketch Posted October 30, 2013 Report Share Posted October 30, 2013 Loc-tite on a barrel nut? WTF? Not having faith that their armorers can torque to correct specs and thus have to rely on loc-tite is a baaaaaaaaaad sign... Grab yourself a KAC Barrel Extension Wrench to make holding onto the upper easier (yes it's AR-10 and SR-25 barrel compatible). Brownells has a similar tool, but I don't think it's as functional since it requires you put the barrel nut wrench in a vise. Oh that is cool takes the hair pullin a little easier I'm guessing it works in reverse too no need for upper block?!? Quote Link to comment Share on other sites More sharing options...
98Z5V Posted October 30, 2013 Report Share Posted October 30, 2013 I'd say Geissele Reaction Rod, but that's only for 5.56 right now. That KAC tool only works with KAC barrels. This is directly from that link above: We're found that it is not compatible with standard AR-15 barrel extensions with square lugs. Only works with KAC barrels. For a similar product for standard AR-15 pattern guns, try the Geissele Reaction Rod. Quote Link to comment Share on other sites More sharing options...
FaRKle! Posted October 30, 2013 Report Share Posted October 30, 2013 (edited) I'd say Geissele Reaction Rod, but that's only for 5.56 right now. That KAC tool only works with KAC barrels. This is directly from that link above: We're found that it is not compatible with standard AR-15 barrel extensions with square lugs. Only works with KAC barrels. For a similar product for standard AR-15 pattern guns, try the Geissele Reaction Rod.Geissele makes a LR308/AR10 reaction rod, but it's $200... The KAC tool does work for AR10s according to Operations Parts:Works with: SR-15, AR-10, SR25, does not work with standard AR-15's Edited October 30, 2013 by FaRKle! Quote Link to comment Share on other sites More sharing options...
TerryF Posted October 30, 2013 Author Report Share Posted October 30, 2013 Thanks, you guys are awesome. I did a little more research on my own and found that I have the DPMS LR-308 barrel nut wrench. I simply had no idea that the wrench engages those flimsy aluminum gas tube holes to pull up to 80 ft-lbs of torque. I ordered a DPMS upper receiver block from Brownells to hold on to. I watched the Brownells video for the AR-15 and like the robustness of the holding fixture that grips the exterior. All I could find was the interior block for the adult-size ARs. Thanks again for getting me on the right path. I plan to photograph and post, assuming DPMS ever sends the new gas block and assuming I don't trash my gun. Terry Quote Link to comment Share on other sites More sharing options...
Skeld Posted October 31, 2013 Report Share Posted October 31, 2013 I was able to remove mine with a strap wrench, but it wouldn't budge until I put some heat to it. I also wasn't going to reuse the nut so I risked using a pipe wrench on it. It turned out that with the heat it came off so easily that the pipe wrench didn't foul up the threads. I can still reuse the barrel nut if I want to. Quote Link to comment Share on other sites More sharing options...
boltcarrier Posted November 3, 2013 Report Share Posted November 3, 2013 I'd say Geissele Reaction Rod, but that's only for 5.56 right now. That KAC tool only works with KAC barrels. This is directly from that link above: We're found that it is not compatible with standard AR-15 barrel extensions with square lugs. Only works with KAC barrels. For a similar product for standard AR-15 pattern guns, try the Geissele Reaction Rod. Sorry -- I was unclear when writing the description of that tool. It works with all AR-10 type lugs and only with KAC 5.56 guns. Quote Link to comment Share on other sites More sharing options...
FaRKle! Posted November 4, 2013 Report Share Posted November 4, 2013 Sorry -- I was unclear when writing the description of that tool. It works with all AR-10 type lugs and only with KAC 5.56 guns.Thanks for the clarification! BTW, the URX 4 I got from you is fantastic! Quote Link to comment Share on other sites More sharing options...
TerryF Posted November 10, 2013 Author Report Share Posted November 10, 2013 OK, the job is complete. I did NOT find thread locker on the barrel nut. I did find thread locker on the threads that join the two parts of the hand guard. I used a DPMS barrel nut wrench, an 18-inch 1/2-inch drive breaker bar and a Harbor Freight heat gun. The upper was held secure by a Brownells upper receiver block held in a five-inch bench vise. The barrel nut came loose quite easily. Thank you all for your kind assistance and encouragement. Terry Quote Link to comment Share on other sites More sharing options...
sketch Posted November 10, 2013 Report Share Posted November 10, 2013 Lookin good bro!! Quote Link to comment Share on other sites More sharing options...
unforgiven Posted November 10, 2013 Report Share Posted November 10, 2013 Nice job brother. Quote Link to comment Share on other sites More sharing options...
seasprite Posted November 10, 2013 Report Share Posted November 10, 2013 Looking good, now its RANGE TIME!!! :banana: Always love the testing part. Quote Link to comment Share on other sites More sharing options...
TerryF Posted November 21, 2013 Author Report Share Posted November 21, 2013 In case anyone is interested, the 12-inch free-float quad rail hand guard is sold by Barrier Defense in Orlando FL. I have no idea who made it. They shipped fast from Gunbroker and charged me $109.00 complete. Terry Quote Link to comment Share on other sites More sharing options...
DeltaEliteMan Posted December 20, 2013 Report Share Posted December 20, 2013 Did the Barrier Defense hand guard come with a new barrel nut or did you reuse your old one? Quote Link to comment Share on other sites More sharing options...
TerryF Posted December 23, 2013 Author Report Share Posted December 23, 2013 D-E-Man, The forend came with a barrel nut, handguard and several three-inch 1913 rail sections w/screws. No instructions, however, which resulted in my cry for help to 308AR.COM. This community is awesome. One of the things I like about this item is that the diameter of the new handguard is much less than the stock DPMS LR-308-B part and it has vent holes. The part seems well made, but I have not subjected it to hard use yet. Terry Quote Link to comment Share on other sites More sharing options...
beachmaster Posted January 19, 2014 Report Share Posted January 19, 2014 Do you by any chance know the weight of that handguard? Quote Link to comment Share on other sites More sharing options...
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