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Old July 28, 2011, 10:57 PM   #1
BobFromAccounting
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New AR-15 Jamming - What Would You Do?

Hello everyone.

I recently purchased a new SOG Armory AR-15. I've taken the rifle out four times now. Each time I've taken it out, I've cleaned and oiled the rifle properly. Unfortunately, each time I've shot it, the rifle will fire, but the case with get stuck in the chamber almost every time.

I called back the people I purchased the rifle from, and they said run 300 rounds through the rifle, and oil the crap out of it, because the rifle is "mil spec" and needs to be broke in.

Is this true or am I being sold a bunch of crap?

Thanks in advance.
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Old July 28, 2011, 11:15 PM   #2
me26245
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Ammo

It could be an ammo issue.

However, a new rifle should run correct right out of the box, or at least whoever you bought it from should pay for the 300 rounds of ammo to break it in.
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Old July 29, 2011, 12:12 AM   #3
HAMMER1DOWN
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Could also check to see if there is any blockages in the gas key tube, I had the same problem, it would be a bolt action AR. ended up tearing the whole rifle down to every last little screw before I figured out the tube was blocked.

Just a thought....
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Old July 29, 2011, 01:23 AM   #4
DBLAction454
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what ammo are you using?
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Old July 29, 2011, 01:46 AM   #5
zippy13
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When you say "the case with get stuck in the chamber almost every time," I'm not sure what you mean. There's a difference between the case getting stuck in the chamber, the action not cycling or the extractor not working -- they might all be called getting stuck. Does the bolt not cycle on it's own, but it will function okay if you cycle it manually. Or, the bolt cycles but the fired hull remains in the chamber.
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Old July 29, 2011, 08:41 AM   #6
DnPRK
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Like zippy13 posted, you need to describe what you see in more detail.

Use American-made brass cased ammo.

Lube the bolt until it drips. If you think you've lubed it too much, lube it some more!

You don't say what the barrel length is. Is it 16"? 18"? 20"?

If it is 16", does it have a carbine length gas system? Or mid-length gas system?

Does the bolt cycle when you shoot only to have the extractor jump over the case rim, leaving the case in the chamber?

Or does the bolt not cycle at all?

Load one round and shoot. Does the bolt lock open? Or does it remain closed?
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Old July 29, 2011, 11:08 AM   #7
James K
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"It needs to be broken in." Translation: "We'll give you the runaround until the warranty expires."

Why should any rifle like that, especially one billed as "mil spec" need a break in? Soldiers don't get a chance to break in rifles; sometimes they are handed one on the way to whatever passes as the front line these days.

Jim
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Old July 29, 2011, 04:09 PM   #8
riverwalker76
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Here's the scoop on new AR-15s.

First off ... MIl-Spec means that it was manufactured with 'loose' tolerances, and should have enough chamber space to keep it from jamming. Never trust the customer service department to tell you the truth. They are given a list of replies to give to customers to get them off of the phone.

Any AR-15 ... I don't care WHO or WHAT make needs to be broken in. A MIL-SPEC AR may or may NOT run straight out of the box with the proper handling. It's a gamble.

Problem #1: Often times the inside of the upper receiver is sprayed with the same paint or coating that the outside is coated with.

Problem #2: The Bolt Carrier Group is treated the exact same way. Spray or dip finish and it is really rough. Imagine sandpaper against sandpaper where you want a nice smooth finish.

Solution: You need to 'marry' the parts together. Oil the heck out of your AR-15 bolt carrier group right before firing it at the range, and run 100 or more rounds of cheap ammo through it. This will smooth out the internals, and get oil where it needs to be. When I say oil it ... I mean ... it should be dripping.

I have built a total of 12 AR-15s from scratch, and I do this with all of them.

DO NOT worry about a gas tube being clogged on a new rifle. That RARELY happens ... even in an AR that has 10k rounds through it.

Try this, and I can guarantee it will smooth out after a few sessions.

Just a tip .... get a tuperware container and fill it with Automatic Transmission Fluid. Soak your bolt carrier group overnight in it, and it will clean all of the 'hard to reach' crud out of the essential areas. Wipe it off with a clean cloth, and throw it back in your rifle.
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Old August 4, 2011, 01:28 PM   #9
BobFromAccounting
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Thanks everyone for your replies.

A little more detail: When the rifle jams, the rifle will fire, but the the fired case will get stuck in the chamber. Other than that, the rifle will cycle and the next round will get stuck behind the empty case stuck in the chamber.

I've used two different ammunition brands, one being Black Hills and the other Remington UMC.

DnPRK: The rifle has a 16" barrel, and I'm not sure about the length of the gas system? How can I tell which one I have?

riverwalker76: I will try the ATF solution and post back results tomorrow. I'm not sure how smoothly the bolt assembly should move in and out of the bolt carrier...when I try to move it (when I have it out of the rifle for cleaning), it seems more difficult to move than it should be. And I'm no sissy.

Thanks again everyone for your help and insights.
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Old August 4, 2011, 04:21 PM   #10
DnPRK
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What you describe, case stays in chamber and fresh round tries to chamber, is the classic Vietnam jam. It is caused by a timing mismatch between the chamber pressure rate of decay and bolt unlock.

A fix is to install a rubber o-ring around the extractor spring.

An additional remedy is to install a heavy buffer.
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Old August 4, 2011, 04:58 PM   #11
Joe the Redneck
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FWIW When I bought my Bushmaster about ten years ago, BM said the same thing about break-in. Get 300 rounds through the gun. I don't think they are giving you "a story".

Don't panic just yet. Get through the 300 rounds before you make any changes to the weapon and see how it goes.

Best wishes

Joe
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Old August 4, 2011, 05:53 PM   #12
Bartholomew Roberts
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Quote:
A little more detail: When the rifle jams, the rifle will fire, but the the fired case will get stuck in the chamber. Other than that, the rifle will cycle and the next round will get stuck behind the empty case stuck in the chamber.
1. When you say it is stuck in the chamber, do you mean that the case has to be knocked out with a cleaning rod? Is there resistance when you go to remove it?

2. Is the rim of the case bent or is there a "bite" out of the rim of the case that does not extract?

Quote:
DnPRK: The rifle has a 16" barrel, and I'm not sure about the length of the gas system? How can I tell which one I have?
A carbine length gas system will have the front sight block about 7-8" and change in front of the barrel nut. A midlength is 9-10" and a rifle length is 12-13"

My recommendations are:

1. Add an o-ring or defender to the extractor and replace the extractor spring with a heavy duty extractor spring (see the Bravo Company extractor upgrade kit) - around $5-7 (see how this works first)

2. Add a heavier buffer - around $20-40

These two will usually fix a rifle that is performing borderline. If they do not fix the problem then you have a bigger timing issue that is likely the result of problems with the chamber and/or gas port. This is something the manufacturer should fix.
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Old August 4, 2011, 06:35 PM   #13
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About 35 years ago I bought a heavy barrel and had the same problem. I pulled the barrel off and really checked the chamber. It looked like they used a tap to ream the chamber. I sent it back and the next one worked fine. We re-barreled and reworked thousands of M-16's. If you need 300 rounds of ammo to break an M-16A-1 look-a-like in, you need to buy from some one else. The Military would run out of ammo "Breaking in rifles".
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Old August 4, 2011, 07:18 PM   #14
BobFromAccounting
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Thanks again for the replies. I must admit, the technical replies to fix this issue are above my level of knowledge and understanding.

Roberts: To clear the jam, I have to clear the to-be-chambered round by pulling the clip out, then pulling back on he charging handle and shaking the rifle sideways until the to-be-chambered round falls out of the ejection port, and then let go of the charging handle to where the bolt is all the way forward. Then I have to cycle the rifle by pulling back on the charging handle, and the case stuck in the chamber will eject.

The rim of the fired cartridge stuck in the chamber is fine, however, I've noticed when the rifle does cycle properly there is a ding approximately 2/3 or 3/4 up the side of the case.

Hope all that makes sense.

This situation is very frustrating, as I dropped 1200 tusks on this rifle on an extremely tight budget and can't afford to cycle 300 rounds and change out parts. I expected the rifle to work right out of the box...perhaps I've been spoiled by my Sigs. FFS though, this is an assault rifle and that term alone implies reliability.

Thanks again for your help. Ultimately, I will take what you guys suggested back to the salesman and let ya know what he says.

I will also take this thread to the salesman and tell him to fix it as you guys suggested, or replace the rifle.

Much appreciated...I will keep you guys updated.

Last edited by BobFromAccounting; August 4, 2011 at 07:24 PM.
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Old August 4, 2011, 07:43 PM   #15
DnPRK
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Pictures of how the o-ring fits around the extractor spring

H2 buffer to replace the factory buffer
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Old August 4, 2011, 08:32 PM   #16
boatbod
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The dent in a normally ejected case is caused by the soft brass case hitting the deflector on the side of the upper receiver. It's normal & nothing to worry about.

Since your fired cases can be extracted normally after you clear the jam, I would agree with the suggestion that this is a timing problem. Basically the bolt & carrier and trying to extract the round before chamber pressure has subsided sufficiently. Once chamber pressure drops, the brass shrinks back a little and can be extracted normally.

A heavy buffer is probably the best upgrade since it will slow the action down. The o-ring mod may work, but it's still going to be hard on your brass.
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Old August 5, 2011, 02:17 AM   #17
ogree
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Since it is a new rifle......perhaps the extractor is defective.
Could also be a damaged or weak extractor spring.
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Old August 5, 2011, 07:25 PM   #18
Jo6pak
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Call me crazy, but if it is a brand new, "mil-spec" rifle, it should run, Period.
I've never seen an AR that did not funtion fine right out of the box.
If not, you should return it before making any mods yourself
If it needs a new Oring, extractor, or heavier buffer tube, I would insist that the manufacturer put them in free of charge.

Just my $.02, you can give me back the change if you want to.
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Old August 5, 2011, 07:54 PM   #19
Powderman
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Try this experiment as well....

At the range ONLY, load two rounds in the magazine. Now, chamber a round.

Immediately eject and inspect the ammunition.

Has the bullet been pushed into the case? If so, CEASE FIRE. What is happening is that the bullet is being pushed into the case upon feeding, causing high pressure that will prevent the case from being ejected.

The solution for that is to use ammunition with a good tight crimp at the case mouth. The Lee Factory Crimp die works very well in those instances.
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Old August 16, 2011, 12:07 PM   #20
Robk
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Now I know there are much more knowledgeable people here, but could this simply be a caliber issue. I do not recall if the OP stated the actual weapon caliber(perhaps I missed it). If mil spec is 5.56mm than there should be no issue. However if the caliber is .223 and the OP is using 5.56mm, than I assume there will be an issue. .223 is commerical and works in a .223 and 5.56mm chamber, however the reverse is not true. 5.56mm loads, but has difficulty coming out of a .223 chamber. I have seen it. The 5.56mm case is ever so slightly bigger than the .223 chamber, causing it to stick. Perhaps? Don't know, but this sounds to me in my opinion could be the case.
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