eggie75 Posted December 27, 2011 Report Share Posted December 27, 2011 hey guys. great resource here. i am no rifle expert by any means and my shooting is recreational. this is my second dpms rifle. the first was an ar15 which i have had no problems what so ever. so when i wanted a .308 i stuck with dpms. i picked up a 308mk12. i am having ejection issues. about 1 or 2 every mag. i've read alot on this subject and have tried the following.pmagspolished the chamber as much as i am comfortable with. i used a dowel and taped 800 grit sandpaper.several different brands of ammosopping wet lube with synthetic oil. i used valvoline because they had a thicker oil available.i don't know how the parts of the bcg should be, but some differences i've noticed between the ar and lr:bolt on the ar moves freely. bolt on lr moves with some resistance.the ejector on the ar is alot looser than the lr. the lr is really stiff.the extractor on the ar is alot stiffer than the lr.can the stiffer ejector and looser extractor combine to cause the bolt to release the spent casing prematurely?the only extractor spring that i can find is the dpms or the fulton but no info as to whether either is original spec or heavier. i'm just gonna order a fulton one and hope for the best. its only $5.or should i just pick up a complete fulton chrome bcg? thanks for any input. Quote Link to comment Share on other sites More sharing options...
Timing Posted December 27, 2011 Report Share Posted December 27, 2011 How many rounds through it? It might be possible it just needs to break in a little. What kind of ammo, surplus? If so maybe try some new stuff. What bullet weight, try a few different types of ammunition and see if the problem persists in each type. Quote Link to comment Share on other sites More sharing options...
eggie75 Posted December 27, 2011 Author Report Share Posted December 27, 2011 about 400 rnds. used:federal 168winchester 150rem ? don't remembersurplus brass 147probs with all ammo.cleaned and lubed before diff ammo. Quote Link to comment Share on other sites More sharing options...
98Z5V Posted December 27, 2011 Report Share Posted December 27, 2011 When you get the FTEs, is the empty case still stuck to the bolt face, or is it just laying in the chamber? You may need to test this with only one round in the magazine. Ensure that the bolt is locking to the rear, but see where the empty case goes. Quote Link to comment Share on other sites More sharing options...
survivalshop Posted December 27, 2011 Report Share Posted December 27, 2011 As said above , need to know what's the position of the case not being ejected. Have you tried different magizines ? I see you say you have Pmags , but were others tried & what was there out come.Polishing with 800 gt. may not be the proper polishing media , flitz metal polish would have been good enough. The springs for the ejector & extractor should be stiff ,but not to the point of being unable to compress them . Check for burr's on the extractor & bolt face area.I also put some Gun Slick grease on the bolt lugs , doesn't have to be that brand ,but some sort of weapons grease will help the bolt unlock until it seats properly , a little goes a long way .I know some that just love syn. motor oil on these rifles , but I'm not one of them & thicker oil is not always better. Quote Link to comment Share on other sites More sharing options...
eggie75 Posted December 27, 2011 Author Report Share Posted December 27, 2011 When you get the FTEs, is the empty case still stuck to the bolt face, or is it just laying in the chamber? You may need to test this with only one round in the magazine. Ensure that the bolt is locking to the rear, but see where the empty case goes.the spent case is half way out and the next round is jammed in at the same time. i don't know if this is a feed or eject issue. i assumed eject since the spent case was still there.this happens out of 20rnds about once. so put in one round at a time?i've tried the dpms mags (2 of them) and pmags (2 of them)no burrs. 800 grit not enough or too much? i saw a thread where a guy used steel wool around a cleaning rod. would that work? or is it too late since i already did the 800 grit?thanks in advance. Quote Link to comment Share on other sites More sharing options...
98Z5V Posted December 27, 2011 Report Share Posted December 27, 2011 This almost looks like an extractor issue - the extractor is failing to hang into the spent casing, and the ejector is popping it loose before it fully clears the chamber, or clears the ejection port opening. Since it doesn't happen every time, and some rounds are clearing, the ejector is working - see if that thing had some stout spring pressure by trying to push it in with a spent case. You can also see if it's sticking in position the same way. Remove the BCG from the rifle, hook the rim of a spent case into the extractor, and press it "straight" onto te bolt face to depress the ejector. Hit that a few times to see if there's any hangups with the ejector, or if the case rim slips off the exrtactor. Quote Link to comment Share on other sites More sharing options...
Coldfoot Posted December 27, 2011 Report Share Posted December 27, 2011 I've had a similar issue. There was a small piece of metal (debris) behind the extractor.You'll need to remove the extractor pin and take a peek. Quote Link to comment Share on other sites More sharing options...
eggie75 Posted December 28, 2011 Author Report Share Posted December 28, 2011 The extractor is clear. Thanks.Ok. with the bcg out, if i put a spent casing in and stand it up, i cannot pull it out straight. so it would seem that the extractor has a good hold. the ejector doesnt seem to stick.bah. was kinda hoping the casing would slip out... Quote Link to comment Share on other sites More sharing options...
washguy Posted December 28, 2011 Report Share Posted December 28, 2011 Hi Eggieput down the sandpaper/dowl and lube, and back up slowly with your hands up <laughs>Firstly an ar and an ar 308 dont feel the same ever on workin parts <laughs> the 308 is usually stiffer on moving parts....sooo we have got to start off with one round in a mag...fire...does the bolt hold back? did the spent shell eject with authority? what does the shell look like any marks? Try a couple of rounds...did the bolt hold open on the last shell? Get rid of that lube get some slp or just use some clp... is it cold where you are shootin....if it is....your lube is too heavy for the cold. get back after you do the function check okay? <thumbsup> Wash Quote Link to comment Share on other sites More sharing options...
98Z5V Posted December 28, 2011 Report Share Posted December 28, 2011 Ok. with the bcg out, if i put a spent casing in and stand it up, i cannot pull it out straight. so it would seem that the extractor has a good hold. the ejector doesnt seem to stick.bah. was kinda hoping the casing would slip out...That just means it's functional under hand pressure - which it should be, for a new gun. That doesn't necessarily mean it functions fine when fired. That test just means "it's not completely screwed," but a serious problem with the extractor would have shown, with that. You could still have an extractor issue here. Try the gun lube first, instead of motor oil, and see where that gets you. Might solve everything. Fire up some results of what happens next. I was kinda hoping the casing would pop out, too - make this easy. <dontknow> <laughs> Quote Link to comment Share on other sites More sharing options...
survivalshop Posted December 28, 2011 Report Share Posted December 28, 2011 Disassemble bolt completely & inspect all components & where they fit . Also check your Carrier key for looseness or blow by .You said your bolt is tight in the Carrier , is it tight the full travel or just in one particular spot ?You have not said if the bolt holds open on last round or I missed it some where , but does it ?Also check your buffer & spring for any tight spots in the extension & proper lubrication . Quote Link to comment Share on other sites More sharing options...
eggie75 Posted December 28, 2011 Author Report Share Posted December 28, 2011 the bolt stays open after last round. the bolt is tight throughout. tight enough that if i pull the charging handle back and let it go forward slowly, the bolt will not advance all of the way unless i push it in. i don't know if that makes sense or not. if i pull it back and just let it go, it will close. maybe this doesn't matter, just tossing it out there.thanks. Quote Link to comment Share on other sites More sharing options...
washguy Posted December 29, 2011 Report Share Posted December 29, 2011 the bolt stays open after last round. the bolt is tight throughout. tight enough that if i pull the charging handle back and let it go forward slowly, the bolt will not advance all of the way unless i push it in. i don't know if that makes sense or not. if i pull it back and just let it go, it will close. maybe this doesn't matter, just tossing it out there.thanks.Hiya Good news on bolt staying open...riding the charging handle slowly will cause the bolt not to go into battery,so thats normal...thats why you pull back on charging handle and let er fly. did you go to a good lube like slp or clp and get that heavy mtor oil off? Wash Quote Link to comment Share on other sites More sharing options...
eggie75 Posted December 29, 2011 Author Report Share Posted December 29, 2011 not yet. won't have a chance to get back out until fri. will report. i'm leaning towards a fulton bcg... Quote Link to comment Share on other sites More sharing options...
washguy Posted December 29, 2011 Report Share Posted December 29, 2011 not yet. won't have a chance to get back out until fri. will report. i'm leaning towards a fulton bcg...Nah you dont have to do that yet <munch>Wash Quote Link to comment Share on other sites More sharing options...
eggie75 Posted January 9, 2012 Author Report Share Posted January 9, 2012 thanks all for the input. went out again today and had 0 failures. i cleaned and lubed up with clr. still had the same issues.i had already ordered a fulton bcg so when it came in i went right back out. 0 failures out of 120 rds. before it was 1 or 2 out of 20. i called fulton prior to ordering and asked if they used dpms cuts and i was told no. upon comparison, i can not visually tell the diff between the two. they look the same and have the same markings in the same places. the only thing that looks different to me is the extractor spring. the dpms has two springs and the fulton has a single with a bushing. the fulton is noticably stiffer than the dpms. overall, the rifle is not having any issues so i am a satisfied customer.i hope this will help someone. Quote Link to comment Share on other sites More sharing options...
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