All,

Ive never been able to get a full magazine without issue (or rarely). I've tried multiple magazines/bullets, holding the magazine (pressing forward/back etc.. and not pressing), once in a blue moon I can get a whole clip or few bullets out. I oiled it up.

My gas block looks aligned and good (though maybe I need to drill dimples for the screws to go into). Heres a slow motion of an eject, it seems like possibly my BCG is not going far enough back. Also sometimes there are little parts of the bullets inside the gun (like the little circle the pin hits to fire the bullet).

Video: https://drive.google.com/open?id=0B8Vi6Zbkyuc6R01JN2h1ODN5eDg

Lower - 5.56 Nato
Rail System: 15" Ultra Slim Keymod Rail
Bolt Carrier Group: Nickel Boron
16" Barrel: 1:7 Twist, Mid Length, Socom

Any help would be appreciated. thanks everyone.

From your post I'm thinking you do not have a lot of experience with firearms, or, in particular, ARs. If you are finding primers in your action you have some serious issues which may be dangerous. I strongly suggest not shooting it and taking the rifle to a qualified gunsmith for a check over.

In the meantime, a couple of Q's:

Did you assemble this AR yourself? If not, who did?

Was the bolt head spaced to the barrel?

What ammo are you using?

Do you know the barrel's gas port size?

JPK

Im definitely new to building/gunning. Ive been around guns, had gun safety classes years ago etc.. but this is my first build.


I assembled the build myself (and the internet).

I built it almost a year ago I dont recall bolt head being spaced to the barrel (I will research this and report back).

Ive used a few different ammos, Israel 556x45mm FMJ Ball, 223,  winchester.

I do not know the barrels gas port size (I will research this and report back).

I appreciate your replies/help. I was hoping to learn and figure it out on my own, but sounds like I might need a professional shops hand/help.

Im not sure its the primer being left over from pictures, its the tiny circle https://maropost.s3.amazonaws.com/uploads/account_206/34642/primerar15.jpg

or seems to be that piece, I should of took a picture of it.

I took a look at the photo in the "link." I see four cases/cartridges with primers with firing pin strikes. The photo appears to show bullets seated in the cases.

What am I looking at?

Dummy rounds?

I'm not understanding what circle you are referring to.

Fwiw, the primers in the photo do not seem to show pressure issues, but did the rounds actually fire?

JPK

Sorry Im learning from your post, so I believe it is the primers Im seeing in my gun/lower sometimes.

That picture was just a random internet picture, ignore that picture, you are correct it is my primers that Im seeing/blow out.

The rounds I shot did fire and eject, but then the next bullet wouldnt load and sometimes a primer from the previous shot would be in there.

sorry for the confusion. Thanks for the help.

You are welcome, happy to try to help. Everyone has to start on the low end of the learning curve...

If you have photos of your fired brass it might be helpful.



Here are some issues which are both concerning and in some cases contradictory:

Your video shows ejection at about 3:30, which is good and should indicate that the rifle isn't too over gassed or too under gassed - but the video shows only one round being fired.

Failure to pick up the next round in the magazine can be either a sign of excessive gas or insufficient gas.

Loosing primers is a sure sign of excessive chamber pressure if you are shooting factory ammo. If you are shooting reloaded ammo it can be a sign of excessive pressure, poor reloading practices or brass that has been previously reloaded too hot or too many times.

I paused the video to get what look I could at the case, and that particular case still had the primer and didn't have any really obvious signs of excessive pressure, but looking at freeze frames of brass being ejected sure has limits...

Usually a quality AR bolt will match with a quality AR barrel and head space will be in spec - but not always. IMO, all new builds ought to have the head space checked before firing since excessive head space can cause extreme pressure issues including catastrophic failure leading to injury and even death. Also, any time a bolt or barrel is changed the head space needs checking.

Excessive gas can lead to excessive cyclic rate, one symptom of which is early bolt opening when chamber pressures are still high. This symptom of extreme over gas mimics excessive head space in some ways since the bolt beginning to open when pressures are still high has the same effect as excessive head space. Your video didn't show some of the signs of excessive gas like a lot of gas from the ejection port or ejection at 2:00 forward.


So, you can see that there is some evidence pointing in contrary directions:
Excessive Pressure:
Primers coming loose

Over gas:
Failure to pick the next round from the magazine
Primers coming loose because of early bolt opening

Proper gas:
3:30-3:00 ejection

Under gas:
Failure to pick up the next round

If it were me, I would start by checking head space since this issue is by far the most serious.

Then I would check barrel gas port size and gas port/block alignment.

At that point I ought o be able to determine, using decent, consistent factory ammo, shot out of several different magazines, whether the rifle is properly gassed or over or under gassed and resolve the issue, if there is one.

Over gassed condition is best solved by the installation of an adjustable gas block or use of an adjustable BCG like the Bootleg BCG, but if the condition isn't too bad can be band aided with a heavier buffer and/or spring.

Under gassed condition, assuming the gas block is properly installed and aligned, etc, is rare, since most AR barrels have gas ports large enough to ensure function of the rifle when dry, dirty and shooting cheap ammo. But, if the rifle was under gassed the fix is to drill, or have someone qualified drill, the gas port to a larger diameter.

In your case, because of your inexperience, I suggest taking the rifle to a qualified gunsmith and asking him if you can watch while he checks head space (which requires a set of go/no go gauges) and watch him set up the gas block so you can see if he did it differently and so you can learn.

With head space confirmed to be within spec, the rifle will be safe with any factory 223 ammo, and you can safely go shooting to determine if the rifle is properly gassed, over gassed or under gassed.

JPK

man you rock, awesome reply.

Okay in the video I was doing the 1 bullet in the magazine test (I read on another post on here, while I was out shooting to test). To see if the BCG would stay open. It did not.  I should of mention'd this on my previous replies.

I think you are correct that the primer did not come out from that bullet/casing but it has a couple times in previous shootings that day, I was barely shooting it, trying to adjust the gas block, oil things up, reseat the buffer spring etc..

Im going to take some time today to go over your replies and suggestions in detail, and hopefully find something standing out.

Was not at my desk through yesterday.

Bolt not locking back can also be a symptom of both excessive gas and insufficient gas. Usually insufficient gas on an unsuppressed rifle.

I'm thinking that in addition to possible head space issues your gas block may be walking forward on you and causing gas port/gas block alignment issues and possibly gas tube/gas key mating issues.

But you really, really ought to have the head space checked!!!

JPK

Something else you can do once you have the headspace checked is remove your bolt from the bolt carrier.  with your upper removed, insert the bolt carrier into the upper receiver and see if you have any spots where it seems to stick.  Excess friction in that are can cause "short stroking".  That would not cause primers to fall out though.  Good luck and post up when you get it figured out so others can learn in the future.

I have a feeling the adjustable gas block moves a little no matter how tight I get it (but when I remove it, the circle/gas seems to always line up for whatever that matters). I think Ill need to drill 2 little bumps for the gas block screws to seat into..

Im taking it to a professional next week, Ill definitely update here, and really appreciate your time/replies.

Are you able to manually lock the bolt all the way to the rear?  

Would you be able to list some more specific details on the parts?  Brands, and specs.

You said the ammo is Israeli. Is it IMI or Independence?  IMI is generally pretty good. Independece can be loaded pretty hot. Couple that with a chamber that is on the tighter side, and that could be the reason you're seeing signs of higher pressure.

You're doing the right thing by taking it to a professional.  The blown primers is a concern and could put you at risk of injury. Let a pro sort it out and resolve to learn a little more in the process.

I'm jumping in here because I'm having similar issues with my new build.   Mine also won't chamber next round, but no loose primers.  Most of the time it ejects the spent casing but sometimes it does not.  Just got back from range with several kinds of ammo - 4 that were various 556 brass, steel, mostly M193, did try one box brass 55gr HP.  Also tried a couple kinds of 223, one steel with polymer coat and one brass.  Didn't think to grab and M855 62gr.

Build is only my second, I made a lot of goofs on first one and did much beter this time (wasted less money too) slanted toward longer ranges - 556 Ballistic Advantage 18" SPR barrell with low-profile rifle legnth gas.  Can't locate the spec on the gas port size, but the barrel came highly recommended.   Areo Precision uppler/lower/bolt.  Passed Go/noGo head space gauges, but don't have anythign more technical than that.   Lock-up did seem a little tight at first, first handful or rounds I really had to muscle back the charging handle.  I thought it might just be brand new parts and the Aero factory FDE Cerakote on the upper that added some thickness that need to be worn down or "broken in".

Lower is Magpul ACS-L from Palmetto lower build Kit mil-spec 7075 buffer tube, spring and buffer.  CMC Drop-in trigger.

Based on these comments seemed like my gas pressure is too low, I tried loosening the gas block, checking alignment and then re-tightening the set screws.  No change.

Also considered the buffer spring might be too strong, but again, can't seem to find any specifications that detail spring weight, is there ever any measurements ever listed for weaker/stronger springs

So at the gun show that weekend I ended up seeing rifle supply guys there, explained my problem and dropped it off that following Monday.  Just got a call today it was the upper machined wrong. I assume that means out of spec or similar.

They put on a new upper and I should be good to go.

I wasn't always getting blow primers. The shop guys also mentioned the same thing you did about hot packed ammo. I will triple check which one I got, but the primers only happened with this last testing with the new can of ammo so it seems very likely.

Ruffly supply guys are pretty awesome, I bought that over a year ago and they handled it fast and easy.

So... that did not fix it, I got to actually shooting out of it this weekend and the same exact issue. I could drop the mag and/or use another mag with the same ammo i loaded and put into other AR15s and fire with out issue.

Im thinking its something with the buffer spring or ???? thoughts :)

Sorry, I reread your posts only, ( did not see the video) and I still don't know what your issue is.

Do you have a failure to feed, failure to extract, failure to eject? What is it actually doing?

Not your guess of whats wrong.

Not trying to be a smartast, I just got a bit confused with all the guesses while not getting what the problem is, and if "pieces of bullets" is related.

Hate to blame it on being under gassed, but most guns are over gassed so they will run any and all crappy ammo.

I have had 3 rifles where the gas port was undersized, with good ammo.

I would measure the size of your gas port.

If you want to check the port size get some small drill bits and and use the smooth end of the bit and find one that just fits the hole. I then measure the bit with calipers.