What causes a double feed?

[7075-T7]

I'm having the same issue with my P238 with DT hardball ammo, it ALWAYS double feeds the last two rounds from either magazine, though seems to work fine with everything else (except buffalo bore hard cast)...

[jiggerachi]

Has anyone else had issues with the disconnecting rod working loose? Is a trip to the smith in my future? Do I send the gun back to the manufacturer? (it is still less than a year old).

Any help/advice is greatly appreciated.

I went through the warranty process for the disconnector spring last year.

Go here
http://www.bersachat.com/forums/showthr ... IC-PISTOLS" onclick="window.open(this.href);return false;

This will tell you how and where to ship your pistol for warranty repair.

Register at that site and post in the gunsmith forum describing what you have happening. Make sure to point out your disconnector spring issue as well. The resident gunsmith will respond with something generic like "send it in for repair and we'll fix it." Respond and tell them it's on it's way. It's a little song and dance, but the post is good to give them a heads up that a pistol is on its way to them. You might even post the tracking number in the thread.

Box it according to their instructions and include a printout of the thread that you posted (or a description of the problem, whatever is easiest). Send it off, they will have it back to you in record time. (This is a new website, they merged the old one into this one, I haven't read much over there since the change, but the process should be the same, your mileage may vary)

This is exactly what I did with my disconnector spring issue, they had it back to me within a week. All I paid was shipping. Ber...ahem, hypethetical Argentinian companies have excellent warranties.

FWIW I sent mine to Colorado Gun Works warranty center, theirs is listed in the instructions sticky post, I highly reccommend them.

[TEX]

In my experience the vast, vast majority of double feeds are actually the result of a failure to extract. On rare occasions two rounds can try to leave the magazine at the same time, but this usually results in one extra live round being pushed out of the ejection port, or hung up in it, with an accompanying failure to fully chamber. Over 40 plus years of shooting and seeing millions of rounds go down range, I have never seen a double feed that when cleared or inspected, revealed a live round in the chamber with another live round behind trying to chamber. In my humble opinion, the word “Double Feed” should be removed from the gun lexicon and replaced with FTE (failure to extract).

Most often failures to extract are caused by a broken or chipped extractor claw/hook, dirt under the extractor, or a weakened extractor spring. This can be exacerbated by a very rough or dirty chamber. The ammunition casing actually swells or expands a bit when fired and if the chamber wall is very rough to begin with or has collected a significant amount of dirt, it can greatly increase friction, thus increasing the force necessary to extract the round - to the point that the extractor can slip or hop over the case rim, leaving the just fired round still in the chamber. The slide then cycles, picked up a new round and tries to chamber it - resulting in a so called double feed. Occasionally a weak load can result in the slide not coming back far enough for the ejector to pop the round out of the ejection port, but this also usually means it didn’t come back far enough to pick up another round off of the magazine – this is rare.

Check the extractor for damage and clean under it well. Polish the chamber and replace the extractor spring. See if this doesn’t eliminate or greatly reduce the double feeds.

[TEX]

Until the slide has almost fully recoiled, the rounds are not even touching the magazine lips. Once the slide comes fully back, the next round in the magazine pops up and rests against the magzine feed lips for a mere split second before the lower portion of the breech starts pushing it from the rear towards the chamber. Using dummy rounds and an empty auto, insert a magazine and then slight pull back the slide about 2/3rds the length of a unspent cartridge. You will see how the top round of the magazine is actually being pushed down by the lower breech rail. This is why a fully charged magazine is easier to insert in an empty (slide back) reload, than in a tactical reload (slide forward). Once a long time ago, I accidently loaded a 40 cal magazine with 9mm ammo and put in my Glock 19. It never did double feed. Upon firing, 1-2 live rounds would spit straight up through the ejection port and the slide would catch one along the way and chamber it, althouh I suspect it was hopping the extractor over that round and not allowing it to slide up under the extractor as it normally would. This would repeat until the magazine was empty. It was both puzzling and halirous at the time. It took me a few minutes and recharging the magazine twice, to figure out what had happned. I have been proven wrong many times in my life, but at this point, I don't buy that loose lips, etc cause a classic double feed. I am not saying it could never happen, but it is certainly not the first place I would look to especially if changing mags didn't change the malfunction frequency.

TEX

[Kevinf2349]

Thanks everyone for your help.

Just to clarify there was definately a live round in the chamber and a second round jammed right in behind it. We had to drop the magazine out, shake out the unchambered round and then clear the one from the chamber.

I think I am going to send the gun back to the manufacturer as suggested above and see what they say.

[Kevinf2349]

I have joined the Ber.....whoops hypothetical gun forum and have emailed the gunsmith to see what we can do. I will keep you all informed of any and all progress.

*fingers crossed*

[JDJ]

Interesting. Sounds like a magazine issue, if both are unfired. My pocket gun can't do that.... ....'cause... the bullets in the wheel go 'round and 'round, 'round and 'round, 'round and 'round. The bullets in the wheel go 'round and 'round, and hit harder than three aye-tee.

LOL!

[trentwhite778]

Sorry to Bring up an old thread. I did a search and only found this one topic so I thought I'd add to it instead of cluttering up the forum with a new one.

I have a Ruger SR40C that I've had for a little over a year as my EDC. I have never had a single problem with it, ever...until today. I went down to Shoot Smart on 35 and bought a box of 100 count Winchester White Box to put a few rounds through the .40 while I was there primarily to break in my new S&W Bodyguard.

Of the 50 rounds I put through it, I had 5 failure to extract (I don't like the term double feed). FIVE! That is an average of one per full magazine. It happened usually on the 2nd or 3rd round an one on the 6th round. I keep it really clean, have only taken it to the range 5-6 times since I've had it in the last year, I'm definitely not limp wristing it and I've never had a single problem with it until today, using this ammo. The first two magazines I put through it were Hornady Critical Defense, because it's just a good idea to shoot the type of ammo that I carry. No problems with it.

Could it be that my gun just doesn't like standard Winchester White Box? I can see no visible damage to the extractor.
Any ideas? Or has anyone experienced anything similar?

[C-dub]

I'm having a real problem visualizing this. Two rounds cannot fit it the chamber. That's just weird.

And I do own a wheel gun. It starts with a 4 and ends with a 4.

[trentwhite778]

The correct term is Failure to Extract. On a semi-automatic, the first round is fired, but the extractor doesn't pull the spent casing out to eject it, causing the next round to be forced in behind it, slide partially back.
Here's an example from googling "failure to extract"

[C-dub]

The correct term is Failure to Extract. On a semi-automatic, the first round is fired, but the extractor doesn't pull the spent casing out to eject it, causing the next round to be forced in behind it, slide partially back.
Here's an example from googling "failure to extract"
[ Image ]

That's what I thought it might look like and what I thought would cause that.

[rotor]

Again, the poster said that both rounds were unfired. That can not be failure to extract. Somehow, it sounds like the top round in the magazine is being pushed forward into the chamber by the second round which is pushed forward by the bolt closing. Normally only the top round is going to be fed. If the top round is chambered and the second round is behind it the magazine is somehow allowing the second round to be driving the top round into the chamber. Would be curious to mark the top round with a red spot and see which round is actually being fed into the barrel and which round is jammed behind it. Have you tried a different magazine?

[TEX]

WAY TO GO ANDYC!!

First time I have ever heard anyone else propose this happening although I have always thought it possible (weak mag spring allowing top round to dislodge from the mag under recoil) and head towards the chamber via the chamber coming back at it during recoil, then the subsequent round being picked up properly and run into the back of the live round that that left the mag in a way it was not supposed to. I have argued this possibility on double feeds where both rounds are live, but I get a strange dismissive look from all that I have said it to, so I quit saying it several decades ago. I have seen a lot of rounds go down range and of the perhaps 50-75 real double feeds (excluding rim fire) I have seen only 1-2 that were not caused by a failure to extract - for whatever reason. On several occasions I have seen magazines with mess up feed lips allow more that one round out, but on every occasion, it spit the first and sometimes second round straight up and out with the slide catching a round and chambering it (the hard way) during this upward cascade of rounds escaping the bad magazine. I have no statistics to back me up other than my own observations, but I would feel comfortable is saying that 95%+ of double feeds result from a failure to extract. IMHO it is very rarely a magazine issue if the springs are good, and why I no longer dump the "in service" magazine when clearing a double feed. I remove it, store in my strong pinky, turn the gun on its side jack the slide a couple of time (while putting finger pressure on the extractor if it is external) , re-inserting the in-service mag and chambering round. It has always worked. This why a good clean extractor, good extractor tension and a smooth chamber are so important. Double feeds take a precious while to clear even if you are well practice at it. Dang, didn't mean for this to get so long.

Good Beans AndyC

[trentwhite778]

sorry for the confusion. The original post was for a double feed of unfired rounds but that was back in 2010. I added onto this thread yesterday because I was having issues for the first time yesterday where the FIRED round was not being extracted and was wondering if anyone else had any issues with that particular ammo as I've never had this problem before. Or if anyone had any ideas on what might be causing it.