308-24-7 Posted February 17, 2015 Report Share Posted February 17, 2015 new to the forum... I am building my first ar10. Using pof lower from my purchase 14.5in gun, new dpms upper, new 24in. flutted ss barrel from Brownells. I am confused on What is the correct gas tube for the gas port @ 12" from the camber. Can some give some guidance? Alsowhat is the best procedure for timing.. I have purchase An adjustable gas block. Quote Link to comment Share on other sites More sharing options...
98Z5V Posted February 17, 2015 Report Share Posted February 17, 2015 Does that DPMS upper work with the POF lower? Quote Link to comment Share on other sites More sharing options...
308-24-7 Posted February 17, 2015 Author Report Share Posted February 17, 2015 I reamed the pin holes in the lower with a .278 reamer from McMaster carr. Perfect fit after that for the dpms pins. I also reamed the pin holes in my pof upper to match. Took a ton of research and head scratching to make it happen. I was very disappointed about pof after I learn they would help me. Quote Link to comment Share on other sites More sharing options...
planeflyer21 Posted February 17, 2015 Report Share Posted February 17, 2015 I reamed the pin holes in the lower with a .278 reamer from McMaster carr. Perfect fit after that for the dpms pins. I also reamed the pin holes in my pof upper to match. Took a ton of research and head scratching to make it happen. I was very disappointed about pof after I learn they would help me. After they would help you or did you mean to put a "not" in there? Quote Link to comment Share on other sites More sharing options...
308-24-7 Posted February 17, 2015 Author Report Share Posted February 17, 2015 Right. Would Not.. no help Quote Link to comment Share on other sites More sharing options...
survivalshop Posted February 17, 2015 Report Share Posted February 17, 2015 (edited) That 24 " barrel should have a rifle length gas tube & because you are mating a DPMS Upper on a POF Lower , they were never made to be mated & there may be a Gas Tube length issue . No way of knowing until you assemble the rifle & & test it . If the length of the gas tube is too short , you can use an Armalite rifle length Gas tube which is longer . Any AR 15/16 rifle length gas tube should work or the longer AR 10 rifle length Gas tube . Fulton Armory sells what they call a 308 gas tube & I believe its just an AR 10 gas tube . We have had some builds here that use different manufacturers Upper & Lowers mated & some need a different Rifle length gas tube & thats where the AR 10 Gas Tube comes in . AR 10 is the designation for the Armalite brand of 308AR , your not building an Armalite rifle , although we know what you mean , but keeping the designations correct helps in part or component identification . From Criterion Barrels ; I believe last time we spoke with Fulton they were using DPMS gas tubes, which wound up protruding about .750 into the chamber. The Armalite tube would protrude about an inch into the chamber, which is a more common practice. I can't speak for Fulton, but I'm guessing they made that change to better accommodate their existing gas port size and slightly reduce the possibility of overgassing the rifle. If you're experiencing excessive recoil then I'd suggest looking into swapping out for an Armalite gas tube on an existing build, but if you're not running into any problems with the shorter tube you should be fine. If you're worried about which gas tube to use on your rifle, I would suggest contacting Fulton directly. We build the barrels to their specifications, so they're probably your best point of reference on how all the pieces should fit together! -Josh Edited February 17, 2015 by survivalshop Quote Link to comment Share on other sites More sharing options...
98Z5V Posted February 17, 2015 Report Share Posted February 17, 2015 ^^^ I knew that information was gonna come in handy. <thumbsup> Quote Link to comment Share on other sites More sharing options...
308-24-7 Posted February 17, 2015 Author Report Share Posted February 17, 2015 OK I will order the armilite tube and try it first. They are not much more than the other brands. I have also heard of people using green locktite around the outside of the barrel where in fits into the upper receiver.. why? Does it make the gun more accurate? Quote Link to comment Share on other sites More sharing options...
Rsquared Posted February 17, 2015 Report Share Posted February 17, 2015 Loctite? Big negative on that. I use a copper-based anti seize compound. Quote Link to comment Share on other sites More sharing options...
FaRKle! Posted February 17, 2015 Report Share Posted February 17, 2015 (edited) I have also heard of people using green locktite around the outside of the barrel where in fits into the upper receiver.. why? Does it make the gun more accurate?Sounds like a crutch for poor barrel nut torque (just like loctite on the receiver extension and castle nut). Edited February 17, 2015 by FaRKle! Quote Link to comment Share on other sites More sharing options...
98Z5V Posted February 17, 2015 Report Share Posted February 17, 2015 The "Loc-Tite on the barrel extension" trick is something that comes from the benchrest bolt-gun bed-your-action crowd. The thought behind it is that if you Loc-Tite your barrel extension to your upper receiver, you've then "bedded it," like bedding a bolt gun. Not the same. Never seen any proof that it works. Never wanna take one apart that has had that schit done to it. Quote Link to comment Share on other sites More sharing options...
308-24-7 Posted February 17, 2015 Author Report Share Posted February 17, 2015 Thanks for your insight. I didnt like the sound of the Loc-tite myself. I hope to have the gun assembled and able to shoot by this weekend.. Crossing my fingers that there is no major issues with the mix bread POF and DPMS parts. They look like a perfect match if not better than the POF lower and upper combo from the factory. Quote Link to comment Share on other sites More sharing options...
survivalshop Posted February 18, 2015 Report Share Posted February 18, 2015 ^^^ I knew that information was gonna come in handy. <thumbsup> I really don't think the gas port in the barrel is a different spec. , I think its all about the many different manufacturers making 308 Upper receivers out there . It is nice to get that kind of info from a manufacturer. <thumbsup> Quote Link to comment Share on other sites More sharing options...
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