So I Purchased a Complete BA upper with 18" .223 Wylde SPR Stainless Steel Rifle Length gas, pinned lo pro gas block; Lantac bcg; Aero Precision m4e1 lower built myself with geissele lpk and ssp trigger, geissele super 42 h1 buffer set. All brand new Pmag gen 3.  I think that's all of the specifics.

First time out, shot through first 2 mags no issues at all, third mag wouldn't cycle, actually closes on 2 of the rounds, the rest just didn't cycle, I had to manually cycle each round.  Broke apart oiled it up a bit.

The next 2-3 mags solid again, then again bolt closed on 1 round, then failed to cycle once or twice, then ran fine after that for a few more mags.  Also it did lock back after final round every time except for one time.  Used all PMC bronze .223 except for 1 mag that had Win white box 5.56 (was only intended to see if I would notice a difference, hence only 1 mag) I also have AE .223 as well as various 5.56 ammo, I've read that the issue could be the ammo, but I would love to get this thing working reliably with all ammo for when SHTF.

Where should I start?  Is this normal for an AR with all new parts including mags? Only thing I'm unfamiliar with is the upper, since I bought it Complete, but I do have a full tool kit to do as I please.  I know the obvious answer is take it to a gunsmith, but for one, I want to know how to fix this stuff myself, that's why I built it mostly myself, and 2 there aren't many credible gunsmiths in my area of riverside county, southern california, none that I know of personally.

If I left out any important info let me know, I'll be watching this post like a hawk!

when you say failed to cycle, what specifically is happening.

Failure to feed? failure to eject? failure to ignite primer? failure to go into battery?

Its not normal. new parts old parts...if everything is correct and functioning it should run like a sewing machine.

PMC and WWB shouldn't  be causing any issues.

OP, the bold above is what has me a bit confused.  Break it down for us....

1.  insert a full mag into the magwell
2.  To feed a round do you: rack the bolt with the Charging handle or just press the bolt release and let the bolt slam home while chambering a round?
3.  Now - aim safely at the target, rotate safety to fire, pull trigger.  What happens?  Pull trigger again what happens.  
 Be more descriptive when you pull the trigger and do not hear a boom.

Did you give the upper and the chamber a good cleaning? Did you lubricate the bolt and carrier before you shot it?

A few times failed to eject entirely.  In others it ejected fine and then closed on the next round half way in the chamber, so it jammed.

did it look like this?

Attached File

when I say closed on the round, sometimes the spent casing failed to eject, but a few times 3-4 to be exact, it ejected but the bolt came back in and snagged the next round when it was half way in the chamber, I now wish I took a picture of that type of jam
1.  insert a full mag into the magwell
2.  To feed a round do you: rack the bolt with the Charging handle or just press the bolt release and let the bolt slam home while chambering a round?
I'm glad you brought this up, because I thought when you hit the bolt release it would chamber a round, but iirc even after hitting the bolt release, I still had to chamber a round manually in order to fire the first round
3.  Now - aim safely at the target, rotate safety to fire, pull trigger.  What happens?  Pull trigger again what happens.  
Be more descriptive when you pull the trigger and do not hear a boom.
so there is always a boom, it never failed to fire, except when using the bolt release alone.  So I load the mag, hit bolt release, click no boom, manually chamber a round, boom, next trigger pull click no boom, manually load chamber empty flies out loads round, then boom. Rinse and repeat.
Then I pulled the bcg out and oiled it, then next couple mags emptied with no issues, then again the above situation occurs again.

I did not clean it prior to shooting.  I did oil everything, maybe not liberally enough?  By this I'm assuming I should clean it and lube it up and try again?

Yes!  That happened 3-4 times out of approx. 100 rounds

My first suggestion would be to try a different mag.  But you are using a brand new Magpul M3.  So that probably isn't your problem.  Next would be a good cleaning and lube.  New components usually ship with heavy grease etc applied.  Sometimes it takes some scrubbing to get that sticky stuff off.  Then apply a nice coat of oil.    I always liked this thread...   https://www.ar15.com/forums/AR-15/AR15-LUBE-POINTS/7-548967/

I'm kind of leaning this way. I always run the first 200 rounds w/the BCG damn near dripping with lube. Clean it well afterwards and lube with a light film afterwards. First AR I bought I didn't do this and had nothing but trouble with it until I did.

Cool, I'll do that first, it makes sense.  Thanks for the link that's definitely helpful.  So the only things that need oiling are the bcg and the trigger components right? But cleaning inlcudes the barrel as well.  Any regular maintenance that needs to be done on the gas tube or system?

Ok thanks.  I'm glad I asked here, because I immediately jumped to a bad component like bcg or buffer. Occam's razor is the answer.

https://youtu.be/bLPF1m6BpD8
Chamber cleaning rod that doesn't rotate

Chamber brush

One piece cleaning rod

Bore guide

Gas tube / system cleans itself.

I learned about the AR-15 platform from ARFCOM, and I found NZ85's youtube channel helpful.  I feel like I learned right along with him. lol

Thanks for all of the info, I picked up a good cleaning kit, already had solvent and oil.  Cleaned it thoroughly and lubed it up, I'll give it another run tomorrow and see how it works out!  I can already smell the freedom.

A couple of mags, then issue, reoiled, and a few more mags, then issue again....
Try a better lube.

make sure your gas ring gaps are spaced out and not lined up...

Keep the chamber clean and dry. Oil in the chamber can almost double the cycling forces. A rough chamber also increases cycling forces. I prefer to polish the chamber, usually before I install the barrel. I use Flitz and a 30-35 cal bore mop with a short section of cleaning rod attached to a cordless drill. To keep out of the leade and rifling, I either drop in a loose bullet or use a wooden dowel inserted from the muzzle to the proper depth and clamped to the MD. Don't forget to remove the bullet and thoroughly clean away all traces of the polishing compound when done. To protect the upper and to keep the Flitz from flying everywhere, I use a 8"-10" section of 3/4" Pex pipe. This may or may not help with your problem, but it's something I do on every build. Some might consider this a waste of time, but I have more time than parts.

So far so good!  Cleaned everything out even stripped the bcg and cleaned every component, and there was some pretty thick almost gooey lube on some parts from factory.  Re-oiled everything with a good quality oil and reassembled.  Went through 100 rounds today not a single misfire, short stroke, etc, ran butter smooth through every mag.  

I'm starting to think you guys actually know what you're talking about! Which is actually pretty rare on forums in general these days.  Thanks again everyone.

Should I run through a few hundred rounds or a thousand rounds and do it again, or just regular maintenance from here on out? Also I have grease and oil, I've heard some guys prefer grease on triggers I think and oil everything else, what are yalls opinions on grease points vs oil points?

Some will disagree but I clean my AR's after every shooting session, no matter the round count. That way you'll get familiarized with the rifle inside and out.

Cleaning I sort of understand, if you love a pristine rifle, but that level of deep cleaning?  What my pops would call white glove cleaning? Or you mean just a quick wipe and oil, without a full teardown?

lol!

Glad to hear you got it shooting, op.  I used to tear my ARs down after every range session for a cleaning and lube.  Then it became every other range session.  Then it became twice a year... and so on....  

I only use grease on my trigger.  I recommend looking at the maint and cleaning section of this forum.  Lots of good stuff.... many many different opinions on grease, oil, cleaning and lube.  Quite a rabbit hole if you're bored one day.

This is an old wives tail and you can prove it to yourself.

Space the rings out, shoot one magazine through the rifle, then disassemble and inspect. The rings will naturally come into alignment after shots have been fired. They will almost always have their gaps in a row once you put a few rounds through the rifle.

New firearms always need to be cleaned prior to shooting them. Always.

The proud new owner has zero idea what preservatives or dirt is in the firearm when they bring it home. A clean tool is a happy tool.

Ahhhh, kinda like when the gaps in ones teeth line up and they can't stop whistling?!

This is the lesson I just learned!  Well my mom always sais I only ever learned through my own mistakes, but since I'm trying to grow up now, next time I'll ask for advise here before any crazy new 2a endeavors lol

I appreciate all of the knowledge from the community.

To think I was sooo close to building my own upper also, and then I found a complete upper actually available and decided that would be best for my first time out lol. Now I'm super glad I didn't.  Maybe the next go around.