Hi all. I have a problem with my AR15. I've read the FAQ and search for what I could, but am still stuck so I'm looking for suggestions. My AR15 is a PSA 18" rifle length .223 Wylde upper with a PSA lower on it. I just bought both new from PSA a month or so ago. I took it out a few weeks ago and from the very first shot, was having malfunction. I took it out again today to try again after searching and trying a few of the simple suggestions I found.

FIRST TRIP: Shooting Federal .223 55grain FMJ bulk ammo. Magpul M3 magazines. With one round loaded in the mag, the rifle would eject but fail to lock back on the empty magazine. With more than one round in the mag, the empty would eject, bolt would return forward, but would not have a new round chambered. I shot 10-15 rounds total, all did the exact same thing. None shot with correct function.

SECOND TRIP: Before shooting, I made sure I lubed everything very well. Few things I found before hand suggested that it may just have been too dry since it was new from the factory. First tried the same Federal 55gr FMJ, exact same results. Next, I shot some Winchester white box 5.56mm 55gr (another suggestion was to try some 5.56 since the higher pressure). First shot got the same results and with the .223, no lock back on the empty mag, or failure to feed the next round before the bolt closed. Trying some more of both ammos though, I started to get different results. I got one where the empty failed to extract. Several where the new round got halfway chambered where it was pinched by the bolt. And then the final one which made me stop trying was the empty case didn't release at all from the chamber. I had to pull pretty good on the charging handle to get it to release.

I took a few pictures of a few of the malfunctions. I also tried a slo-mo video on my phone.








Firing portion of the video starts around 45 seconds.
<iframe src="https://player.vimeo.com/video/221341107" width="640" height="1138" frameborder="0" webkitallowfullscreen mozallowfullscreen allowfullscreen></iframe> <p><a href="https://vimeo.com/221341107">Untitled</a> from <a href="https://vimeo.com/user67680061">Grant Rolfes</a> on <a href="https://vimeo.com">Vimeo</a>.</p>






Thanks in advance.

Grantis2911

What kind of buffer and spring are in it?

Everything is stock from PSA.

Did you clean out the chamber and bolt/carrier really good?

Yes. It was clean from the factory, and I did a full breakdown and lube before firing.

If it is not locking back on a empty mag then you need more gas, or a lighter buffer

Should that happen on a new rifle? Or should I send it back to PSA?

Or, the mag is not inserted enough.  Press the mag release button in as far as you can and rotate the other side a turn or two.  This will raise the mag and could solve all your problems.

Txl

Brand new guns are tight.  Brand new AR-15 type guns are going to have stoppages until they break in.  The finish on the moving parts is like friction tape.  It impedes the smooth operation of the action.

It take 300-500 cycles to start the break-in process.

You describe some intermittent failures to eject.  That can happen when the ejector spring insert is missing or defective.  Sometimes a problem with short recoil (low gas pressure) can cause the bolt to extract the fired casing, but not eject the casing because the bolt is not traveling all the way to the rear.

PMags do not work properly in many lower receivers.  I have some PMags that don't lock into AR-15 Lowers I have tried them in, before I took a file to them.  a ridge molded into the magazine as a stop to revent over-insertion was keeping the magazines from locking in.  Have you tried other magazines?  I find Genuine USGI magazines (not Commercial magazines made to GI Spec) to be much more reliable with most AR-15 type guns than PMags and other plastic magazines.  (Exception the USGI magazines are great rule are some Genuine USGI magazines supplied by Brownell's that are too wide to fit and drop free on any of the AR-15 Lowers that they were tested on).

You can kick-start the break in process by cleaning the entire gun with gun solvent and a brush.  Then, without lubrication, reassemble the gun, and manually cycle the action using the charging handle at least 200 times, 500 times being better.

After that, clean the gun again with gun cleaner, and lubricate normally with gun lubricant.  The gun should operate much smoother now, but but might not fully chamber a round without a tap of the forward assist.  This will improve as the fired round count increases.

Since you assembled the gun, you should have been checking the parts for proper fit.  Proper fit is not sloppy.  A new gun will not be smooth in operation until after break-in as already explained.  When you assembled the gun you should have been watching for machining burrs, and that all moving parts click into detents properly.  Even on preassembled uppers you should be checking that the gas block is properly positioned and the fasteners are properly tightened.

I recommend breaking in firing Federal M855 5.56 ammo.  Not Commercial .223 or no name surplus ammo which is loaded to a lower pressure.

Know it is not popular suggestion, but if it were me, I'd call PSA and talk to a rep.

PSA lower with PSA upper and problem keeps repeating, then it is a PSA issue.

They will send you free shipping label and return ship you a new upper.

Scrub the chamber with a chamber brush and solvent before you start fiddling with part change out other than mags.

Sounds like it is undergassed. Maybe they didn't align the gas block correctly. PSA uses a carbine buffer by default, so it is the lightest (standard) buffer you can get.

I have the same upper but I haven't shot it yet. I was planning on trying an H2 buffer to smooth it out more, but that would be the last thing you want to do if it is undergassed.

It does lock back on an empty mag if I pull the charging handle back again after firing the single shot. Still something I should check?

Sounds under gassed to me.

Check gas block alignment over the port.

Sometimes if LP gas block are pushed all the way back to the "step" on the barrel, they will not be 100% centered over the gas port. Loosen your set screws, and slide the block forward the thickness of an end cap used with drop in HG's/pinned FSB's and see what happens.

Definitely sounds like it is under gassed.

Update: Had some time to shoot again with a few different magazines. Worked right away without malfunction. With continued shooting I did get where it didn't lock open on the last round about 50% of the time. I then tried my original Pmags and worked just like the other mags.

I still plan to brush it all down with a solvent still but I think it is starting to break in. I just never realized the break in period came with so many malfunctions.

Thanks for the help, I'll be back if it continues to give the same last round malfunction.

That still sounds above and beyond any expected break-in issues. My first AR has honestly never had a stoppage in over a thousand rounds. I think your rifle is still undergassed.

Your brass looks like the chamber is not finished properly.  Case grabbing the chamber can mimic undergassing.

This. There is no "break in period" for an AR to get it to function correctly.

Is it something that is potentially going to cause problems? Or will the finish "break in" even though it maybe shouldn't have to?

Can't say. I bought a set of the 400 and 800 grit chambers hones a good while back that I use if a chamber on a non chromed or hardened barrel looks a little rough when I get it. I only mess with them because I rarely send stuff back. Usually I just mess with it and it works or gets thrown in the junk box.

If it is new maybe just get with the company explaining the problem and see what they say.

All new guns need to be broke in before they reach the reliable stage.

Read some Owner's Manuals that come with factory assembled pistols and rifles.  They all mention the break-in period.

New guns are like any other manufactured/machined metal product.  The manufacturing process leaves rough spots and burrs with the finish that needs to be worn-in.  Stainless steel gun parts are especially prone to having edges that need wearing in.

Dry cycling the gun as I have recommended is one way to shorten the break-in and burn fewer rounds of ammo during the process.  You must wear the finish down smooth on the moving parts if you expect the gun to work properly.

A rough chamber needs to be returned.  You can polish it yourself, it may wark, it may not.  If it does not, you cannot return it.