I am looking for some help ....

I have bought a barely used-Armalite AR15A4 Carbine that takes finicky to a whole new level.  I have seriously cleaned the chamber and normal brass-cased ammo still sticks!  You have to extert a tremendous amount of force on the cocking handle to extract an unfired round.  During firing after about 5 rounds it develops Feed Failures with the bolt not going all the way into battery, or FTE with the case sticking in the chamber...

Since my Colt HBAR feed any and everything without complaint, I am at a loss of what steps to take troubleshoot this rifle.

Thanks for the help!

James Flowers

Now you know why it was barely used  [>:/]
I would suggest going to the Armalite website and read the tech notes (#50) for your rifle to start with.  [red][url]http://www.armalite.com/[/url][/red]
Some suggestions:
Incomplete charging/ejection cycle due to low gas pressure - misaligned gas port at front sight, pinched gas tube, foreign object in gas tube or carrier key, buffer spring mismatched or bent.
Damaged magazine - try two other magazines.
If that doesn't work I'll give you $20 for it and even pay for the shipping.[;D]  GOOD LUCK!

Actually, since I knew the former owner, I knew the fact that he had only shot it once or twice before I bought it.  The first time with no problem, and the second with a FTE (but he had never cleaned the gun).

Thanks for the info from Armalite, but my problem is much simpler....

If I load a round from a magazine... lets say Bosnian SS109 from a Sanchez USGI... it loads fine.  But to manually extract the round from the chamber requires significant effort.  I have noticed that the ammo has some serious scratches in the bullet after extraction.

At this point I am assuming I have either a very rough chamber or a chamber that has something hard fouling it.  I have scrubbed the chamber several times and can not see anything.

So, any suggestions on ways to troubleshoot this are welcome.  I guess the last chance fix would be to have the chamber re-reamed or the barrel replaced by Armalite.

Thanks

Have you tried different brands of ammo?  Different batch #'s?
Sometimes a .223 bullet in a new 5.56 chamber will be too tight.  OR if the projectile was crimped incorrectly it could expand the case shoulder.  I have only come across this once and the whole batch was bad (Machines loading bad batches).
ARMALITE has always been helpful when I call them for tech stuff...
Sorry I couldn't help.  Let us know what the problem was when you figure it out, that's how we learn here.
Welcome aboard by the way.

[B]Sometimes a .223 bullet in a new 5.56 chamber will be too tight.[/B]

Don't you mean a 5.56 might be too tight in a .223 chamber?

Troy... Thanks for the thoughts!

I tried several different ammos through the gun.  Black Hills VMAX and Q3131A were much easier than Bosnian SS109 or Wolf 55gr HP to manually extract, but I noticed that each round I ran through the gun had a matching scar along the bullet from just behind the tip to the case throat.... possible across the case to the shoulder.

Any thoughts on why or what could be scarring the rounds?  I am assuming that I still have a rough spot in the chamber/throat somewhere.

A rough spot is sure what it sounds like.  Take a look at ArmaLite's Tech Note 32.

(I would send the rifle back to ArmaLite for repair if it was me.)

5sub

i had a similar problem with my new 15a4.
it would not eject the spent shell out of the chamber. i sent it back to armalite and they polished the chamber.
i havent had a single problem since then (500rds).
i find it amazing though, that they said all rifles are test fired before leaving the plant.
because their was no way the spent casing was coming out of that chamber without some serious
pushing with a rod.

Yep.


5sub

Remember that Armalite is not the true and famous Armalite that you think of when you hear the name.

The company formerly known as Eagle Arms purchased the Armalite corporate name to help bolster their faltering sales.

They do not make weapons in the tradition and high quality standards that the old and since deceased Armalite company did. All today's Armalite is...is a company that was about to go bankrupt but was saved by the assumption of a new and famous name.

Hey, it worked, what can I say.

My answer to your question...but a Colt or a Bushmaster. They set the standard. Everyone else just tries to keep up.

The marks you describe here are from the ejector forcing the cartridge against the locking lugs when its extracted from the chamber and forced towards the ejection port.Should be two marks running parallel with each other.Thats normal,mine does the same thing.
I would look for marks(rifling marking the bullet) right in front of the case neck all the way around the bullet ogive.
If your M15 is one that was made prior to 2001 it has a .223 Rem. chamber.And a tight one too,and a pain in the ars,trust me.
I had the same problem with my M15A2 that was Purchased new in the spring of 2001 and it would only function properly with UMC and Fed Eagle .223Rem. spec ammo.
Wolf,PMC,Q3131A and some of the Black Hills would chamber but the bullets were forced into the rifling/leade,marking the bullets and were darn hard to extract manually.Not to mention the function issues I had.Man I was hating life there for awhile since my $900.00 new AR would not eat very much of what I could find.Picky would be putting it lightly.
The spent cases also showed signs of pressure with primers that were very flat.
I contacted several ammunition manufacturers about the ammo issue and Wolf was the only one that responded.WolF said that the wolf .223 was loaded to SAAMI specs but was on the long side of the spec.So it may cause problems with the tighter chambers.And it does trust me.But so did some PMC 64Gr.sp and the Q3131A.
Try chambering a round with the foward assist.If its hard to get the round to complete the chambering and some force is needed you have the tight .223 Rem chamber.
I finally gave up on calling Armalite about it trying to get something done.All I could get from them was that the rifles will shoot any NATO spec ammo,and if I wanted a 5.56 chamber they could replace the barrel.I could not see paying them close $300.00+ to swap the new barrel on my M15 for a new 5.56 barrel when I could get a whole new upper for less than $500.00 and not have to wait three+ months on the repair.So,until I get the money saved for a new upper Im just shooting UMC .223 Rem. in the Armalite.
HTH

I have an M15A4 that was running somewhat hesitantly with Q3131A. I was getting a stovepipe or two per magazine. I got a chamber cleaning tool from GA Precision, covered a chamber brush with patches soaked in Shooter's Choice, and cleaned a dismaying amount of gunk out of the chamber and locking lugs. My boresnake with Break-Free just wasn't cleaning the chamber adequately. It feels like a different gun now.