benny hill Posted May 29, 2013 Share Posted May 29, 2013 Sorry, left out the word "lock" Link to comment Share on other sites More sharing options...
M ammo Posted May 29, 2013 Author Share Posted May 29, 2013 Sorry, left out the word "lock" I have been ,,, adjusting the Gas block,, and just about the time I run,, 10 or 12 rounds,, and I'm getting all happy,,, F#@!$$$$K FTE Making the buffer heavy, helped allot, Fail to extract,,, is still the problem,,, so somehow,, getting the gun to pull out that brass, is my goal,, At this point I don’t care if it rips off the case head.. just as long as it pulls something out of the gun,, Link to comment Share on other sites More sharing options...
bigbrowndog Posted May 30, 2013 Share Posted May 30, 2013 Here is more info on the gas situation that Jim forgot to mention, when we were shooting if you turned the gas adjustment screw in, to cut off or lessen the gas the gun would throw brass3-5 feet away from the gun, but if you opened the port up to give it more gas it just allow the brass to trickle out of the gun, maybe 1-2 feet away. Going to the heavy buffer only bandaids the issue it does not solve it, the gun still only runs 5-15 rds and then malfs, when we tried the BCG from one of my guns it would be the same thing so it doesn't appear to be a BCG issue. Also my BCG runs just fine in my gun it went thru 50 rounds just the other night at piggies!! it could easily be gas tube, gas block, barrel port, chamber, or simply the interface of all the gas related parts. His load seems to be a good middle of the road load for a 155gr bullet, 2700ish fps. We also tried shooting my ammo in his gun, also a 155gr bullet at 2700ish fps, and got the same issues. We thought that his gas tube being a bit shorter than mine (1/4") was the issue but he replaced it with a slightly longer one and still has the issue. I think its a parts problem stemming from too many different makes and manufacturers. Anyway Jim will probably be shooting a LaRue OBR with the new Bushnell Tactical 1-8.5x at RM3G, so don't feel too bad for him. trapr Link to comment Share on other sites More sharing options...
Mike P Posted May 30, 2013 Share Posted May 30, 2013 I was having what I thought were extraction problems with mine. Though it wound up being the ejector. The new onwewas a little different. The thing has been running great after changing it. Link to comment Share on other sites More sharing options...
M ammo Posted May 30, 2013 Author Share Posted May 30, 2013 Here is more info on the gas situation that Jim forgot to mention, when we were shooting if you turned the gas adjustment screw in, to cut off or lessen the gas the gun would throw brass3-5 feet away from the gun, but if you opened the port up to give it more gas it just allow the brass to trickle out of the gun, maybe 1-2 feet away. Going to the heavy buffer only bandaids the issue it does not solve it, the gun still only runs 5-15 rds and then malfs, when we tried the BCG from one of my guns it would be the same thing so it doesn't appear to be a BCG issue. Also my BCG runs just fine in my gun it went thru 50 rounds just the other night at piggies!! it could easily be gas tube, gas block, barrel port, chamber, or simply the interface of all the gas related parts. His load seems to be a good middle of the road load for a 155gr bullet, 2700ish fps. We also tried shooting my ammo in his gun, also a 155gr bullet at 2700ish fps, and got the same issues. We thought that his gas tube being a bit shorter than mine (1/4") was the issue but he replaced it with a slightly longer one and still has the issue. I think its a parts problem stemming from too many different makes and manufacturers. Anyway Jim will probably be shooting a LaRue OBR with the new Bushnell Tactical 1-8.5x at RM3G, so don't feel too bad for him. trapr Thank you! Trapr,,,,,,,,,,,, I appreciate the Loaner, more than I can tell you, ,,,,,, JJ (RM3G) always asks if I'm going to shoot He Man, to get the numbers up in that shooting class,, and its fun to shoot the smaller divisions,, too,, hey everyone needs someone to beat!! But then again with a Gun that is going to work, I can concentrate on shooting the match and not gun smiting mid stage,, I have been fighting this gun for a long time,, now I'm just to stupid and stubborn to give up on it,,, Some day this gun will work,, and I’m sure in the end it will be something so Obvious it will be embarrassing, but on the other hand, I’m not the only one with this problem, lots of AR’s in 308 have this same problem. If I had the equipment, ( Machine Shop) to do some real machining, I would re-design the bolt with an extractor twice the size of the one, currently on 308 bolts, with double springs. Link to comment Share on other sites More sharing options...
DEP44 Posted May 31, 2013 Share Posted May 31, 2013 Had extraction/ejection problems with my 16"AP4 when new. I replaced the extractor spring with heavy duty Wolff spring, didn't help. Mostly the empty would be pulled from the chamber and just lay on top of the magazine. I ended up using 2 rubber o rings around the extractor spring (smallest they had at Ace Hardware store) which cured the problems 100%. Beyond my expectation they are holding up and they appear to be oil resistant. Jut thought I'd mention it, as its a cheap thing to try. Link to comment Share on other sites More sharing options...
M ammo Posted May 31, 2013 Author Share Posted May 31, 2013 Had extraction/ejection problems with my 16"AP4 when new. I replaced the extractor spring with heavy duty Wolff spring, didn't help. Mostly the empty would be pulled from the chamber and just lay on top of the magazine. I ended up using 2 rubber o rings around the extractor spring (smallest they had at Ace Hardware store) which cured the problems 100%. Beyond my expectation they are holding up and they appear to be oil resistant. Jut thought I'd mention it, as its a cheap thing to try. thanks,,, I got some,, but have not had a chance to try it,,, the ones I got look a lil big,, I did get the smallest ones they had,, but I will try to put them in. and OR,, I'll look at some other hardware store,, for some others, Link to comment Share on other sites More sharing options...
pyrrhic3gun Posted June 1, 2013 Share Posted June 1, 2013 The size o-rings you want are 1/8" ID X 1/4" OD. At my Ace hardware they are labeled #1...but I notice the standard for that size calls it a -006. Link to comment Share on other sites More sharing options...
fastshooter03 Posted June 1, 2013 Share Posted June 1, 2013 @ the CMMG match I had to put in two 223 extractor blue bumper things into a squadmates DPMS 308 before it would reliably extract. Put one on each side of the extractor spring. Ran two stages without jamming after mod. Told him to polish out the chamber as well. I don't remember the barrel or gas length. Nick Link to comment Share on other sites More sharing options...
1ltrng3bn Posted June 9, 2013 Share Posted June 9, 2013 here's my 2 cents worth: I've had 5 dpms lr-308's. all had problems,but the ap-4 was the really troublesome one.I think you cannot address extraction w/o addressing bolt thrust/dwell time. to that end, I have concluded the big rifle should have no shorter than mid-length gas system, rifle length is best.here is what I've done to keep my rifles running: because my rifles seemed ok til I ran a field course and burned down a mag or so, then failure to extract, case left in chamber,ect.To cure that problem I use the dpms dual spring set-up+ 2 tanks rifle shop dognuts( stacked). Change them every 1000 rounds...keep a log.I know it seems like a lot of spring pressure,but that 1.75lb. carrier group slamming home will strip a round w/o any problems & extractor will snap into place.Now your spring will not fade from a hot gun:read lots of double taps.what else I change: all my rifles have standard buttstock exts. w/ a-1 stocks( only slightly longer than an ar15a2.I use tubbs +10% recoil springs, with enidine standard .308 buffers(big increase in dwell time/unlocking)I also use pof roller cam pins.now my rifle runs, and brass is not torn up.Finally, a jp ajustable gas block.Now ,brass looks great ,no extractor/ejector marks, and all it cost was time & money Link to comment Share on other sites More sharing options...
1ltrng3bn Posted June 12, 2013 Share Posted June 12, 2013 just came back from initial break-in of my latest lr-308. based on the current M-110 concept, it has a fulton armory 20"1-12,4 groove barrel. gas system is rifle length. I added an enidine a-2 buffer,tubbs h/d recoil spring ,a pof roller cam,a jp enhanced bolt. and a jp adjustable gas block. ammo is 168 hpbt @2600 fps.followed directions- set screw 2 turns up from bottom. fired a round, bolt locked back.1 1/2 turns,1 turn,same thing. at 3/4 turn, pierced a primer.At a full turn it was ok, but hi primer flow...settled on 1-1/4 turns.Couple of points here: 1,it does not take alot of gas to function big gun.2,there needs to be enough gas out to not create unwanted pressure in chamber. will continue to use adjustable gas block to tame big gun. Link to comment Share on other sites More sharing options...
Szczinator Posted June 13, 2013 Share Posted June 13, 2013 Ok, ok, ok.... Ok, I've had this problem with two .308 rifles. Currently a DPMS-3G1, and previously a DSA SA-58 (FN FAL). The FN would either not extract or not eject. The extracted case would not be ejected and the bolt then tried to chamber both the empty case and the next round in the mag. The FN was many years old, with all original parts and well used. The extractor was worn and the spring was 3/16" shorter than the new one I put in. New extractor, new spring = instant fix. I only got rid of it because of 3 min MOA accuracy @ 100 yd. Not good enough for 3G The DPMS did exactly the same thing when it malfunctioned. But being a brand new rifle I failed to recognize the problem for what it was. I thought the ejector was bad. What was happening is the extractor was releasing the empty case before it was ejected. So since it no longer was in contact with the bolt face, the ejector had no contact with case to eject it. Like a dummy I forgot all about the FN and cursed DPMS. Refer back to FastShooter03 @ 4:41 pm. Nick w/Team X-Rail. He woke me up. We took the bolt apart and found the spring under the extractor was naked, no plug, no donut. He had a parts kit with him at CMMG Midwest 3G, but AR Parts. But like he said, he took two (2) AR plugs and put one on each end o the spring and we forced it to fit the pin. It worked. I had been using Mil-surp 147 & 150 gr mostly foreign, and 168 gr BTHP from GTG. (Good to Go Ammo) in McKinney, Texas (sub-moa groups @ 100 yds) After the fix Nick did I finished the rest o the match with no malfunctions. I Chronographed the ammo I was using. Ten rounds each in all my mags while mono-podding. No problems. By the way the Mil-surp ammo ranged from 2600 - 2700 fps, the 168's avg 2450 fps. No other modifications have been done to this rifle (yet). I do plan to have the BCG NP3'd by Robar. Makes it slick and easy to get the carbon off. I have also read that you cannot over lubricate these temperamental beasts. Hope this helps. Thanks again Nick. Link to comment Share on other sites More sharing options...
Szczinator Posted June 13, 2013 Share Posted June 13, 2013 Mistake: Nick's post was 01 June 13 @ 6:41 Link to comment Share on other sites More sharing options...
Szczinator Posted June 13, 2013 Share Posted June 13, 2013 Oh yeah, almost forgot, Most definitely, positively, absolutely have to polish the chamber. I want to see myself in it. Link to comment Share on other sites More sharing options...
M ammo Posted September 23, 2013 Author Share Posted September 23, 2013 At Long last,, after MUCH,, pain and suffering,, The Gun runs,,,, what did I do,,,, Changed out parts until The gun worked,,, the only thing that is now DPMS,,, is the upper,,the lower and the charging handle! The Gun is now a JP,, --Rainier Arms Barrel Bolt and carrier,, Jp trigger and gass Block,, I adjusted it Just like Benny said,,, and the gun runs,,, Thank you for all the Help,,, Link to comment Share on other sites More sharing options...
DEP44 Posted June 5, 2014 Share Posted June 5, 2014 Got mine ordered today: http://www.dpmsinc.com/DPMS-G2-Extractor-and-Elastomer-Sprint-Kit_p_2521.html Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now