Well I just got back from the range shooting my new DPMS G2 Recon 308. The rifle was a single shot for all my 40 rounds. I had to mortar the first 20 or so rounds, then it got to where I was able to use the charging handle to cycle the bolt. It seemed like the bcg wasn't fully locking forward after picking up the second round and using the FA did nothing but I dont know why the bcg would be in such a bind either so I dont know.  Anyway I thought I read on here of someone with similar problems or something but now I cant seem to find it, so any ideas

Nope, all stock.

Sounds like it could have a tight chamber? Also, have you taken the BCG out and inspected it for any apparent flaws or abnormally tight bolt to carrier fitment? Also, I hope you lubricated the rifle well as new rifles can very very tight, normally not tight enough to seemingly not go into battery all the way though.

Just grasping at straws as the details are a little vague and there are no pictures.

Lastly, what ammo where you using?

It sounds like a gas issue, Check the whole system from gas rings to carrier key all the way to the gas block

Sorry I didnt get any pics but I greased the bcg on the bcg rails and cam pin then break free CLP the bcg.  I run all my AR's like this, its very messy but they stay well lubed.  The ammo was fed premium 165gr trophy bond.

Edit I did pull the bcg and checked for function before and after shooting, no problems.  

Your right, the tight chamber may account for me doing the mortar procedure and thinking that the buffer spring wasn't strong enough.  Is there any way of me knowing with out buying a go no go gauge?

In the OP you mentioned it was a single shot, as in not ejecting as well as chambering issues?

If I'm understanding your description correctly, it sounds similar to a problem S&W .308 that came back to the store several times. Short story is bad chamber and gas block not properly aligned with the port.

Myself I've also had mag lips dragging causing bolt to slow down but it wasn't an AR. Just tossing the thought out.

I never rule out defective ammo as I've seen a lot of recalls over the years.

And speaking of ammo I put an adjustable gas block on my G2 Hunter. In trying 5 different powders in handloads it became very apparent there were big differences in the pressure curves, etc between the powders. What worked perfect for one powder/bullet combo didn't work for another.

To clarify since I really didnt give a good description of the single shot problem, the rifle will shoot and eject the first round and it will load the second round it just will not shoot the second round.  I have to eject the second round and then reload it.  The ejected round looks fine with no marks or scratches but some had a very light impression of the firing pin on the primer and some didn't.  Also the DPMS mag looks like shit, the rounds do not contour to the feed lips at all and the follower looks like its sitting crooked half the time.  I was thinking it could be a mag problem but it will load the next round so thats all you can ask of a mag.

Still a vague description of problems.

So, your first round chambers fine from the mag when you drop the bolt from the rearward position (using the bolt release)? Then it goes bang, ejects, feeds the second round and then click and nothing or you pull the trigger and hear nothing?

Also, mag issues are easily identifiable even if you don't know really what to look for. Simply try another mag, preferably one that looks good and see how it shoots. If it still fails and you are convinced it's still the mag, try a different brand mag. That can be done in just minutes while at the range.

As to your comment about firing pin marks, the free float design of the firing pin causes that light dimple from simply the inertia of the action cycling or bolt being released. If you have some with and without marks, my first though is you are riding the carrier forward with the CH instead of releasing the bolt and letting the buffer spring move the carrier forward at the correct speed to chamber the round and lock the bolt into battery. You should still be able to use FA to push the carrier into battery, although some new rifles may not go forward as easily since they can be very tight.

With that said, your problem could be as mentioned above-> gas issue, but doesn't explain the FTF unless the rifle is short stroking enough to cause the carrier to loose some velocity, and maybe more by compounding the potential magazine issue and it's not 100% in battery. Again, just grasping at straws.

Have you removed the FCG from the rifle at all? I cannot count the number of times I have seen a hammer spring installed backward causing light strikes.

Based on others experience, I would NOT send the rifle back until you have exhausted all options in terms of "quick fixes", or at least identifying what the root cause is before sending it in.

Customer service related to other GII owners has been pretty pathetic, you may not see your gun (or a replacement) for multiple months, and it may come back with other problems.

Another guy here had a problem with the carrier getting stuck in the buffer tube. Mine hits the edge of the buffer tube but doesn't seem to cause any issue on functioning. If I understand your problem right, if the carrier is hitting the buffer tube and getting hung up, perhaps that is the issue? Not really sure, I'd think the spring would have just as much force moving the carrier forward as the carrier broke free of the buffer tube, but maybe not.

Just something to look at. Its very apparent on mine where the carrier hits the tube, and I've seen some very small metal shavings which I believe come off the tube.

IIRC another issue with the carrier/bolt is the ejector pin coming out, but you'd have noticed that.

I went back out, same problems but decided to disassemble the bcg and look things over again.   I did take some pics, still the mag is the only thing I see any problems with
 

FWIW the mag that came with mine didn't work at all.  It failed to load properly on a consistent basis.  I bought some pmags, did a little filing on the followers and they work flawlessly. You could pick up one to try, not do the filing and see if it works. If it does then you could modify to allow it to engage the bolt catch, if not you could return it.

Feed lips are curled over way too much from what I can see.

It looks like the right leg of the hammer spring is below the trigger pin.

Nota Bene: Internet advise from an insomniac at 3:30 am.

Please examine the photograph of the interior of the upper showing the chamber. Examine the barrel face. The area to view particularly closely is the top left. To me it looks like there have been five strikes from the tips of the bullets impacting the barrel face, when the cartridge was being loaded. I have seen this same phenomenon when using Galil mags in a .223 Valmet. It is not merely undesirable it is dangerous.

To restate, it appears that the cartridges are being held to high, and as they are pushed forward, the bullet tip is striking the barrel face, and only then possibly entering the chamber.

Please add more photos. I have Dykem marking blue, but anything which can stain a surface could be used. Apply it to the bullet tips, and see it is transferred to the barrel face. If this is indeed the case, hopefully it could be solved by something simple, like trying several magazines and seeing if it only happens with one of them. If not it is a serious problem which must be addressed.

DB

Edited for clarity

As LRRP has stated. The feed lips of the one magazine photographed do not conform to the circumference of the brass. They appear to hold the base of the cartridge to low which may position the tip too high.

Edited to add: If this is indeed what is happening the bullet may be set back deeply into the brass and only then fed into the chamber. This could result in a serious over pressure. I would not want to do a destructive test of a barrel extension and bolt. I certainly would not want to do this unintentionally.

East Texas,

Go to your nearest Academy and buy a Magpul 20 round mag for your rifle. DPMS metal mags are shit.

UPDATE:  Rifle now runs!!!  Local gunsmith I was talking to wanted to have a look at it.  Luckily he has a gun range right there in his shop.  He had the same problems as I did and after playing with it and resetting the gas block and looking it over on about round 16 he started playing with the selector.  The selector and disconnector were some how binding up just enough to where he could feel a difference in it between charging a round in vs when the rifle cycled.  He went to show me and could replicate it twice but then not any more.  So he said lets try it and see if the gun will shoot a mag, sure enough it did.  Then I bought some more ammo and went out on my own and the rifle ran like a champ.  All this was with that factory DPMS mag, I was planning on changing the trigger and selector anyway but wanted the rifle up and running first. Also last night I ordered 2 Larue 7.62 metal mags, and have some Lancers on back order too.  On a side note my firing pin is bent and a little eroded and covered in a lot of carbon as was the pin keeper.  I guess eighty rounds or so must be close to the life of these firing pins?  

No.  You're off by couple orders of magnitude.

I'm sure it's dirty, but there's no way it should be eroded.  Let's see a picture.

Ill try to post some pics later on but here is just two threads I found yesterday on it.   Damaged G2 Recon firing pin,   DPMS FIRING PIN CHIPPING

Glad you worked out the issue.  One question, did you install JP springs?  Your Hammer spring looks yellow, like the JP 'Light Target Only" springs they sell.  Any other changes to the rifle?

It came factory DPMS with no changes from me.  Im color blind but to me the spring looks green, so IDK???

They come with a green spring.

Yeah, thats definitely green, thanks.  Looked yellow on my phone for some reason.

I didnt realize the 2-stage also came with a reduced power hammer spring.  My G2 Bull came with grey/brown springs, promptly swapped for an ACT ALG w/Tan spring until I can upgrade.  I gotta say though, the standard FCG in there was pretty good.  I know with GI FCGs its usually luck of the draw though.

You most likely had a primer pierce and that burned the tip of the firing pin.

Once the tip is burned you will get more primer piercings.

It also bends the retaining pin from gas traveling down the firing pin aperture.

I had the same thought also. I had functioning problems with JP springs and refuse to allow them to touch my rifles.

My Hunter came with your standard colored AR springs. Now sports a LaRue.

OP what ammo were you shooting?

Glad its running for you.

I am the OP about the chipped firing pins.

What ended up going on is the bolt face firing pin hole was too large and I was getting a lot of cratered primers and an occasional pierced primer.

I was not aware of the pierced primers due to shooting a few magazines and my son would do the same, we would pick up all the brass not really paying attention to the dirty brass until it was time to start re-working the brass for reloading.

Anyway, I sent my GII hunter back to DPMS to have it worked over.

The gunsmith was really good to work with and re-worked my bolt face, polished the chamber and customized 2 firing pins for my rifle.

As of now my rifle runs great and I have had no problems at all.

My firing pin was not chipping but was eroded from pierced primers. I could have sworn the tip was chipped by looking at it with a magnifying glass.

My mistake. I had the rifle re-worked and changed to #34 primers and have never looked back. I hope I can get a 6.5 someday.

This is good news, if the firing pins are all being damaged from pierced primers due to the too-large firing pin hole.  The large firing pin hole was part of the early runs, but DPMS has changed the design to be smaller and stop alot of these issues.  So they've basically already fixed the problem.  Not sure what serial numbers include the new bolt design.