ltwguns.com

Here's something I've been meaning to do for a while.

Question: is it really, truly harmful to your 1911's original-style, internal extractor, to drop a round in the chamber and then drop the slide on it? Of course there are other good reasons not to do that, such as, chicks like guys who dance and you can dance better with all your toes....

OK, so say we never, ever do the above. What about that occasional push feed, where, under certain conditions, the round gets pushed ahead of the closing slide, and, instead of the case head gliding smoothly up the breachface and under the extractor like it's supposed to, the round gets in front of the extractor and the extractor has to clip over it (or the slide stops short of battery because the extractor has not clipped over the cartridge rim)? I've seen 1911's that will do this very reliably under certain conditions.

A chap who posts by the name of, I believe, Johnny, on 1911 Forum, gave a very good slow-mo sequence of events describing a push feed, and also gave some good tips on extractor end shape to help the extractor overcome the problem, should it happen. Another fellow, in the name of science, dropped his slide on an empty case, I don't remember how many times, to find out. Sorry to say I can't produce links, I might try harder later though. I can tell you that I was inspired by these posts to fill out that spot on the back of my drivers license, so now, when I die, my 1911 will be donated to science also .

As I think I mentioned in a previous post, the extractor on an M1 or M1A1 Thompson submachinegun snaps over each and every round and is very similar in size and shape to that of a 1911-- of course, it doesn't really do the extracting since these guns are straight blowback and as such would work without an extractor, so I can't say they aren't harmed by the process. And besides, with the case sitting in a full-round boltface recess, tension would be not-so-important, but-- as far as I know they are not known for breaking.


Well, this evening I rigged a 1911 so that it would push feed every time, and also modified it to fire full-auto at a rate of 750 rounds per minute, took it out and fired 12,000 rounds through it.

Well, sorta.

I took an extractor and took a very precise measurement of it, clamped up a certain way, so that I would be able to detect any changes in its shape. I then rigged it on my mill with a piece mounted in the spindle that, when spun, would cam-flex the extractor with each revolution. I set the speed at 750 RPM and let it run for 16 minutes, or 12,000 flexes. I set it to flex .060, which is a LOT more than it would have to flex in a slide-drop or push feed. At the end of the testing it was only flexing .045 due to some wear on the bronze piece that was swinging around and contacting it every revolution..... bear in mind this was very spur of the moment, I'll do more testing later, and a little more carefully, but even .045 is about what it would actually have to move.

At the end of the test, there was not change whatsoever in the extractor's dimensions, not even one thousandth of an inch.

Not the be-all, end-all test, but it does say something.

At this point I'd like to say that in my 1911 article in a recent SWAT Magazine (Jan 05), I said that dropping the slide on a chambered round MAY affect extractor tension

did you by chance test the tension of this extractor prior to and after your test?

Thanks for the effort and info Ned. I've been curious about this myth for a while. From the way the extractor was designed, I didn't expect it to be able to flex that much for an extended amount of repetitions without getting bent.

I'm guessing you clamped the extractor at the base. Does the slide offer that amount of clearance for the extractor to flex that far because I notice most extractors have that hump in the middle. I'm not sure what it's purpose is for, but if that hump rests on the slide, it will restrict the extractor's full movement. The flexing distance would be shorter.

Thanks for taking the time, Ned. I always found Johnny's (1911Tuner's) posts, e-mails, and tests to be informative and humorous. Tests and corresponding posts help us all learn a bit more about our beloved 1911s.

Be well!

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damian@adcofirearms.com
http://www.adcofirearms.com

Nice to have my little test fall on science-minded ears, good questions, guys. I did not measure tension before and after, but in the next test I will do so. The fact that there was no dimensional change does not necessarily mean no change in tension (but I'm betting there is no change).

This extractor was actually a broken Wilson Bulletproof. It broke at the head, where the neck-down corner intersects the Series 80 cut. This is a weakish spot in all Series 80 extractors, and I'm surprised that more don't break here; I've taken to filletting this area ever so slightly. Anyway-- with a little filing, I had the rear flat section to clamp onto, and that's what I did, right behind the rat (my "pet" name for the hump in the middle-- looks like a snake swallowed a rat). So, the flexing was occurring from the rat forward as in actual use.

The Wilsons have been very good extractors for me BTW. This is the first one I've installed that came back broken, of any brand, actually, discounting a guy who I will refer to as The Chief, who has broken eight 1911 extractors in the last 40- years, of all brands, factory, aftermarket, fitted by a variety of people. The Chief and his bad extractor karma are another story though.

The next test will be a little more thorough and scientific-- I'll measure tension, and use a whole extractor, new, and mount it in a little fixture so that the rat is the actual rear contact point. Stay tuned to 1911 MythBusters. And hey, this is a communal show, like Public Access TV, anybody can get air time here.

Damian, would you please locate Johnny and invite him over?

EDIT! Just re-reading this old post and it's not 40 years, it's 4 years.

Ned,

When your test device cams, is it impacting the tip of the extractor before it caues flex or is all the action happening from the side? Just trying to visualize what your device is doing. Or is my question clear as mud?

Johnny is most often found moderating and replying to posts in gunsmithing section of The High Road.

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Jeff

It is sorta wiping on the angle of the tip, like a round would. I do intend to change the motion profile for the next test though, to more accurately simulate ramping over a ctg. and then snapping down onto the rim. Right now the profile is very close to that but not exactly.

Hey Ned - I've got an old FUBAR slide that I'd be happy to send you if you want one to cut up and use as a fixture to hold an extractor while you test it.

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Dave Berryhill
Berryhill Custom, LLC

I'm not a metalurgist, an engineer, or a scientiest though I did watch PBS Kids with my son this morning...

Just wondering how much energy/damage is done when the extractor impacts the rear of the case before camming over the rim. It would seem that that point would have the highest impact energy. That "hit" slows the slide down as it cams over the rim.

I'd think that would be the cause/reason for any breakage over flex. It's held in place by the firing pin stop and the spring steel is being forced to compress and not bend.

Just the ramblings of broken man drinking coffee on a cool and rainy Saturday morning. Infused with just enough knowledge to be dangerous at any speed.

Or am I way off base and looking at this all wrong?

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Jeff

Wow, Ned, this is a very interesting research project. Thanks for the time and effort.

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Sic Semper Tyrannis

Yep, You have my attention Ned. Like I said at Shot I would hate to be you. Constantly waking up at night yelling "make it stop" Anyway, this could end up answering several extractor related questions.

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Heirloom Precision, LLC.
480-804-1911

"If everyone is thinking alike, someone isn't thinking."
- General George Patton Jr

Ned, Interesting post. I'm wondering in those instances where a shooter claimed that their extractor broke from a cam-over if the extractor bore in their particular slide was either a bit small or full of grunge. If this happened, I could see where the extractor would try to move outward to clear the rim, but encounter a solid resistance to any further movement. In a case like this, I wonder if your hook would go or would the rim? Brass being softer, I'd figure the brass, but I suppose there are extenuating circumstances.

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Don Williams
http://www.theactionworks.com
http://www.ltwguns.com

mrbieler, I can't discount the impact thing, although I think the first test duped that to some degree. It's not such a direct impact due to the ramp in the front (which varies somewhat from brand to brand).

Did some more testing this AM. The extractor was held in a cut-in-two slide (thanks anyway Dave, had one, Crown City Arms, 'bout the only thing it's good for is gettin' sawed in half). I made a more elaborate cam to more closely simulate the goings-on when we have a push feed or a Bubba-feed (Bubba-feed: when Bubba drops a round in the chamber and lets the slide slam down on it. You will find this not in Webster's but in Nedster's). I picked out a brand new EGW extractor 'cause I figured George could take the heat .

I set the tension on the extractor and installed it, and again measured the hook position very precisely. This time I also measured tension, not in the usual manner, but rather how much direct side pressure it took to deflect the extractor .010. Then I set it all up to cause a total deplection of .048. The profile was, deflect .048, snap down onto the crowding surface of the extractor (which was .038 deep so still at .010 deflection), then come off completely. I let it run as before at 750 RPM for 16 minutes. Took it all down and remeasured..........

[drum roll]............................[/drum roll]

No changes, nada, zip. The extractor had not bent even a single thousandth, and the tension (7 1/2 pounds) had not changed a bit. My cam had not worn so there was a full .048 deflection from flex one to flex 12K. Now the 7 1/2 pounds may sound heavy but remember that's not measured in the usual way, I wanted a direct reading.

Have you thought about jerry rigging the extractor to reduce the amount it can flex to simulate powder build up?

You rock, Ned.

In a scary sort of way.........

Thanks for the first installment of 'Myth Whackers'

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CT Brian Custom
'Blending Art With Firepower'

Glad to see you doing this, Ned.
Bob Dunlap, the head gunsmith guru at AGI (those folks that make all of those gunsmith tapes) has challenged this before too. His analogy- extractors are springs (supposed to be made of spring steel) that flex much less distance and many fewer times over its entire life than the valve springs in your car flex in a day.

Badger, I haven't.

CT, I like MythWhackers much better, thanks, and with credit and a tip o' the purple velvet, gold-tasseled LTW fez to you, I have changed the title of the post!

I have the feeling that several people out there, probably not readers here, or not all of them anyway, reached the end of this little extractor knowledge quest a long time ago. This stuff surely has been learned and relearned many times since the days of JMB.

I am starting to see that the likely culprit in extractor de-tensioning and breaking is ejection, and not feeding or extraction. I will eventually do some cycle testing along those lines but for now I need to get my nose back to the grindstone

Great test Ned. Keep up the good work. Also, congratulations on your article. It was great. So, when is the next one.

Cheers,

Fred

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"Walk softly and carry a big stick."
Theodore Roosevelt

here's some comments by 1911tuner on the m1911 forum re: dimples on followers and how they related to losing extractor tension:

http://forum.m1911.org/showthread.php?t=1959

(read down to post #7 in the thread).

-k

Ah, 1911Tuner.

There is a lot of not very good advice given on the net by people who don't know as much as they think they do.

1911Tuner is not one of those people in my book. Everything I've read by him makes sense and shows a very in-depth understanding of the 1911 and things in general. Not that he needs me saying that to make it so.

Yes, I started this post sounding like I was gonna dis him, that's meant as a friendly elbow to him, a little professional courtesy joke if you will. He'd be very welcome here.