Bushmaster double feeding

[osiruscyn]

My buddy has a bushy that is a couple of years old. Ever since he's had it, it's regularly double fed bullets. He's tried various mags (20 rd w/green follower, and other various mags) with the same results. One round will go into the chamber while another one will get fed and up at an angle and get jammed up in the top of the chamber. He sent it back to bushmaster when it was under warranty and they said they couldn't replicate it. Any thoughts as to what it could be?

[gasrings]

Double feeds are almost always magazine related.

Aren't green USGI followers for 30 round mags; not 20s?

If the mags have been modded, that opens up the possibility that the springs were reinstalled upside down. If so, they may not be able to be loaded to full capacity... green followers in 20s would do that too.

Do the mags work in other ARs?

[osiruscyn]

haven't tried the mags in a different AR. That's what I thought to, that it was mag related but he has a couple of different types of mags and it does it with all them he says. I'll have to ask him about it and maybe take it to a range and see if he can try some of the different mags there and see if it still happens.

[Mnukedude]

Wild coincidence here: Could all the magazine springs be toast at the same time? Has he tried to replicate the problem with a new, box stock magazine?

[PlasticGuy]

A double feed is not a magazine issue. It's almost always an extractor issue. AR-15 extractors often need one of the "upgrade kits" to get enough tension to be reliable. It's a well documented issue with the AR-15 design. The other issue is that the extractor claw may be rounded off or chipped. I'd just replace the extractor and install an upgrade kit at the same time. I'd bet you 10 to 1 the double feeds clear up immediately afterward.

[DJ Niner]

My buddy has a bushy that is a couple of years old. Ever since he's had it, it's regularly double fed bullets. He's tried various mags (20 rd w/green follower, and other various mags) with the same results. One round will go into the chamber while another one will get fed and up at an angle and get jammed up in the top of the chamber. He sent it back to bushmaster when it was under warranty and they said they couldn't replicate it. Any thoughts as to what it could be?If the jammed rounds are both LIVE rounds (going by the definition of a double feed), it has happened with several magazines of different pedigrees, and the factory couldn't replicate the problem (even though it "regularly" does it when your buddy uses it), then I'd say it's some kind of user-induced problem. Especially if it only happens during initial loading. Have you ever watched him attempt to load and shoot it?

If it happens during firing, and one of the cases involved in the stoppage is empty (in that case, they shouldn't have both been referred to as "rounds" in your description of the problem, above), then I agree with the diagnosis of a failure to extract, with the bolt leaving the empty case in the chamber and moving back far enough to pick up the next round in the magazine and attempting to chamber it. Check extractor condition (damaged lip?), and extractor spring tension.

[slammed89swb]

I have to agree with Plasticguy I had the same problem with my bushy and I upgraded the spring and added an o-ring to my extractor and no more problems!

[WolfiePacker]

the o rings work wonders. all of my ARs will have them.

[gasrings]

A double feed is not a magazine issue. It's almost always an extractor issue. AR-15 extractors often need one of the "upgrade kits" to get enough tension to be reliable. It's a well documented issue with the AR-15 design. The other issue is that the extractor claw may be rounded off or chipped. I'd just replace the extractor and install an upgrade kit at the same time. I'd bet you 10 to 1 the double feeds clear up immediately afterward.

You're describing a failure to extract. Looks like a double feed, but isn't. DJ Niner already covered the finer points of each.

http://www.ar15.com/content/page.html?id=64

[PlasticGuy]

You're describing a failure to extract. Looks like a double feed, but isn't. DJ Niner already covered the finer points of each.

http://www.ar15.com/content/page.html?id=64
I guess it depends on the semantics of whatever schools you train at, but a failure to extract with a round attempting to feed into it has been called a double-feed at most of the schools I've been do (or a type 3, if you prefer).

I've never seen a rifle try to feed two live rounds at the same time, at least not with with a variety of mags. That is pretty hard to imagine that it's doing that with every mag he has on hand. I believe he's describing the aftermath of a FTE.

[DJ Niner]

(snip)

I've never seen a rifle try to feed two live rounds at the same time, at least not with with a variety of mags. That is pretty hard to imagine that it's doing that with every mag he has on hand. I believe he's describing the aftermath of a FTE.As do I, but the way the problem was initially described leaves lots of room for interpretation, and the fact that Bushmaster was unable to replicate the stoppage pushed me toward a user-induced problem. Improperly/poorly/un trained users can come up with some seriously strange stuff.

Should I tell you about the guy who always loaded his AR with the bolt locked to the rear, inserted a magazine, depressed the bolt release (which chambered a round) and then pulled and released the charging handle (ejecting the first round and chambering a second)? :shocked:

Oh, wait. I just did. :)

He SWORE that this was how he was taught by his uncle to ready the weapon for firing (Army veteran). I often wonder how many rounds he left on the ground at the range over the years...

After explaining in detail how the weapon functions, we got him straightened out, but he had been doing it this way for 15+ years, and no one had ever said a word to him. I'm not saying the OP's buddy is this screwed-up, but just watching a person operate their weapon can tell you a lot about how well they understand it.

[PlasticGuy]

As do I, but the way the problem was initially described leaves lots of room for interpretation, and the fact that Bushmaster was unable to replicate the stoppage pushed me toward a user-induced problem. Improperly/poorly/un trained users can come up with some seriously strange stuff...
No argument here. There's been more than a few instances in classes I've taught when I've had to stop the class and ask a student, "What in the world are you trying to do, and who in the heck taught you to do it that way?" Anything is possible, I guess.