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Old January 24, 2013, 07:53 PM   #1
Balog
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1911 feed lips: two different styles?

In another thread, the excellent source of knowledge on all things related to his username 1911Tuner wrote this:

Quote:
"We'll address that a little later, with photos that illustrate the two basic different feed lip designs and how they affect the angle of entry. Might be better on a separate thread since this one has kinda gone wide of the mark."
I had never heard of variations in the feed lip design for 1911's, and since I intend to switch my carry piece to that design soon I'm very interested. Starting this thread to find out what this is all about.
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Old January 24, 2013, 08:01 PM   #2
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Just two? You wish. I'll leave it to a 1911 aficionado to go further.
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Old January 24, 2013, 08:02 PM   #3
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Old January 24, 2013, 08:26 PM   #4
1911Tuner
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Lips

While there are three, the "Hybrid" is actually a combination of the two basic types. A sort of a "Best of Both Worlds" thing.

Before we go further, the two different designs differ in subtle ways, but...depending on the ammunition...can make a lot of difference.

We'll start with the "Wadcutter" design.

Back in the day that the excellent Hensley&Gibbs #68 SWC bullet set the standard for Bullseye, the only magazines available were the "Hardball" units with their full-tapered late/gradual release. While some pistols would do quite well, many wouldn't. So, the AMU armorers developed an anvil and forming die to create an early, timed release point.

Later development toward the parallel lips and the even earlier, abrupt release point allowed the use of SWC bullets that were of shorter nose and larger full-diameter bullet sections. They worked well as long as the ammunition was downloaded to "Softball" levels and the lowly little bump on the top of the follower was left in play.

That bump is important. It prevents the last round from jumping the magazine under inertia when the slide hits the impact abutment, thus maintaining full control of the round, as per design. Remove it, and you run the risk of the last round being fed ahead of the extractor and either causing a stoppage...or forcing the claw over the rim...which leads to loss of extractor tension and outright failure.

The wadcutter's release is also a little too early and too abrupt for most ammunition suitable for defensive or anti-personnel use.

The GI "Hardball" magazine, with its late, gradual release has no distinct release point, and holds the cartridge rim until the rim is almost completely captured by the extractor...and it has only a short jump to the final position when it finally does release.

The "Hybrid" is Colt's own design that appeared about the same time as the Series 80 pistols made their debut. It combines the gradual release of the GI magazine, with the timed release point of the wadcutter type, though slightly later and less abrupt. The cartridge rim is under the extractor, but not quite as far as the full-tapered GI magazine places it.

The tapered lips cause another interesting effect. The cartridge rises at th rear as the bullet noses up to enter the chamber, giving it a straighter shot at the chamber than the wadcutter magazine does, all but eliminating the round from having to literally climb a hill and break over to horizontal as it reaches the final entry point.

The picture below illustrates this. Here, both magazines are 7-round capacity,and both have the standard flat follower with the dimple on top...which incidentally stops the round just before the release point.

In both magazines, the cartridge is pushed forward so that the leading edge of the are rims are stopped by the dimple on the follower. Note the difference in the positions of the cartridges. By this point, the Hybrid's gradual release has let the extractor start to pick up the rim, while the wadcutter's final release literally forces the rim to "jump" for it...and sometimes it misses.

In the picture, both cartridges are pushed forward to exactly the same place...against the follower dimple.

Photo courtesy of 2009 C. Kaukl - All Rights Reserved

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Old January 24, 2013, 08:28 PM   #5
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A picture's worth a thousand words.Three types indeed.
Now the question :What's this thread about?There are theses on the subject
but there could be something new to be revealed,new is good.
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Old January 24, 2013, 08:31 PM   #6
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Curiously, while as far as I know all new Colt full-size and Commander-size pistols ship with either 7-round or 8-round magazines with the "hybrid" feed lips, the only Colt magazines I've ever seen for the Officers ACP and Defender pistols use the true wadcutter feed lips -- and both are generally 100 percent reliable feeding JHP self-defense ammo.
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Old January 24, 2013, 08:36 PM   #7
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OM

Quote:
the only Colt magazines I've ever seen for the Officers ACP and Defender pistols use the true wadcutter feed lips
I've seen the wadcutter types more recently...but the early ones had the "Hybrid" type lips. I think I've even got a couple here of that design.

Incidentally...the term "Hybrid" is mine. I coined it and Check Mate Industries adopted it when I was helping them develop their 8 round magazine and their patented "Bull Nose" follower. I also provided them with the dimensions for a gauge to test and set the release point for their full-tapered Hardball magazines.
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Old January 24, 2013, 08:40 PM   #8
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Reelations

Quote:
What's this thread about?There are theses on the subject
but there could be something new to be revealed,new is good.
Nothing new at all. John Browning and the Dream Team had the answer over a hundred years ago. The problem is that so many people have been trying for so long to prove that they're smarter than those guys...they really believe they've succeeded.

Go back and look at the picture, grasshopper...and let your mind understand what your eye sees.
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Old January 24, 2013, 08:58 PM   #9
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So, purely from a reliability stand point would the hybrid or GI be better? And what are some good examples of each? Gonna start buying mags soon.
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Old January 24, 2013, 09:10 PM   #10
1911Tuner
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re:

Quote:
So, purely from a reliability stand point would the hybrid or GI be better?
The GI design is at its best with hardball and its nominal 1.260 OAL. As the cartridge gets shorter, it starts to need a timed release point. Again, the "Hybrid" offers the best of both worlds and will work equally well with either as well as the Hensley&Gibbs #68 when loaded to about the same OAL, or a bit shorter. I like that one at 1.250, but YMMV.

The 1911 was designed on the controlled feed principle. The gradual release...which actually starts earlier but with a later final release...maintains control of the round until the extractor has picked it up.

A point that I've made so many times over the years:

The 1911 was designed to function. As long as it's correctly built to spec and fed decent ammunition from a proper magazine...it will function. It doesn't have a choice. It's a machine.
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Old January 24, 2013, 09:35 PM   #11
Billy Shears
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Wow. I've been shooting 1911s almost my entire life, tens of thousands of rounds shot and mags lying all over the house, and I did not know this. Thank you, 1911Tuner & WVsig, for sharing your knowledge & experience so freely with us.

This thread ought to be stickied.
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Old January 24, 2013, 09:55 PM   #12
polyphemus
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feed angle

The first magazine I measured was a seventy year old Scovil,that was 20 deg.
on the money,then all three different types from modern manufacturers and
all regardless of configuration were consistently 20 deg.as well.The approach
angle then being the same,the variables are a)spring pressure b)point of release.
Not all manufacturers seem to subscribe to the raised bump theory and the skirted type follower appears to be more of a reassuring feature than a useful
one,interesting to mention is the the convex type which appears in some Wadcutter type magazines.
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Old January 25, 2013, 12:08 AM   #13
1911Tuner
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A Degree

Quote:
The first magazine I measured was a seventy year old Scovil,that was 20 deg.on the money,then all three different types from modern manufacturers and all regardless of configuration were consistently 20 deg.as well.
If you'll remove the recoil spring from a pistol and feed a round from a tapered/gradual release magazine slowly enough to see what the cartridge does, you'll notice something interesting that doesn't happen with parallel feed lips...something that isn't apparent with a static measurement.

The cartridge moves up at the rear as it moves forward...as though it's being lifted on a cantilever. By the time it's completely released, it's almost dead horizontal as it enters the chamber...with very little breaking over remaining.

But the angle of approach and entry isn't all there is to it, my one-eyed friend.

Look at the picture again. The rim at the left is a full 1/8th inch higher on the breechface than the one on the right...under the extractor...and the magazine hasn't even released it yet. "Controlled Feed" means just that. Controlled feed is the secret that makes the 1911 one of the most reliable designs to come down the pike...as long as full control is maintained.

Quote:
Not all manufacturers seem to subscribe to the raised bump theory
That's mainly because so many people have been trying to outsmart Browning for so long, they really believe they have. Either that, or they flat don't understand why it was put there in the first place...or maybe both. I stopped arguing with Mose 35 years ago.

About 20 years ago, give or take...a friend of mine bought that little 5-dollar paperback by Ken Hallock. Ken advised removing the "pip" because he didn't deem it necessary...and he theorized that it was a hindrance to smooth feeding on the last round. "Joe" immediately began experiencing...issues...ranging from the slide locking back empty with the last round lying loose in the port...to loss of extractor tension that kept returning...and ultimately a broken extractor that broke again in less than 2,000 rounds. I fixed him up with a new extractor and loaned him a dozen magazines. His problems vanished along with the burrs on the edges of his rims that caused problems with his shell holders.

More recently, another friend from Tennessee that I met through THR was having several problems with nearly all his 1911s. I had to do a little actual work on a couple of'em...minor stuff mostly except for the one we dubbed "The Norinco from Hell." Mostly, I handed him a few of my magazines and watched the look of amazement come over his face. He thanked me publicly for "The Gift of Reliability" and it was mainly because of the magazines he'd been using.

Quote:
the skirted type follower appears to be more of a reassuring feature than a usefulone,
The skirted followers appeared after the appearance of the Devel 8-round magazine that disappeared for a time, and was picked up by Chip McCormick and used in his Shooting Star magazines...and the same problems surfaced.

The follower wasn't stable because the rear leg only had two spring coils to nail it to the rear wall on the last round instead of three provided by the standard 7-round stick. It pitched forward and caused misfeeds on the last round, and it damaged aluminum alloy frames...something that the standard 7-round followers don't do. There were also common complaints of failure to lock the slide on empty. Chip responded with the Powermag, with a heavier spring...which helped, but didn't eliminate the problem. Needless to say that the unstable follower didn't do well at all with the dimple because the case rim dragged it forward with a vengeance.

Check Mate's Bull Nose (tm) follower is no more than the Kelsey/Devel follower with a skirt and a dimple on top. When they finally started using a decent spring...and extended the floorplate of the magazine one cartridge length, concealed with a false slam pad...their 8-round magazines started working. It took me 6 months to convince'em, but they finally threw in the towel on that extension, the full-length 11-pound spring, and the dimple. Their 8-round magazines...parallel or hybrid lips, as per buyer's choice...are constantly backordered. They're as good as any I've tried.

It's time to point out that I have no financial interest in Check Mate Industries, and I receive no compensation from them beyond the half-dozen magazines that I got for beta testing and input. They've since been passed along to other testers...as per the agreement...and I don't have them any more. CMI could go belly up or it could come to dominate the magazine market, and it wouldn't affect my portfolio one penny's worth. All I got for the GI feed lip gauge was a "Wow! Thanks!" But it's ai'ght.

The "Hybrid" design was all Colt's, and in addition to CMI, they've also had contracts with Metalform and OKAY for the magazines. It's just that CMI is the only vendor that will sell them to the general public without the Colt logo, unless you happen to catch Metalform with a few overruns from a filled contract without the horsie on the floorplate...but don't expect to score more than a half-dozen at best.

Quote:
interesting to mention is the the convex type which appears in some Wadcutter type magazines.
Do you know what single function the convex follower performs that the flat follower doesn't? It's more of a band-aid that compensates for a lack of something than anything else...and that advantage is compromised by the use of an extended ejector, even if it doesn't touch it.
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Old January 25, 2013, 11:35 AM   #14
Balog
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Ok, so I've been doing some research and it's somewhat frustrating as the places selling the mags generally don't specify if the follower is dimpled, what style feed lips etc.

So if I want to buy a passel of 8 round non-flush fitting (which eliminates the compromise issues of squeezing an extra round in the same magazine length right?) flat dimpled follower hybrid feed lip magazines: what brand and model numbers should I look for? Especially given how many places are out of stock on the better known brands I'm getting worried about being able to feed a 1911 (if I can find one).
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Old January 25, 2013, 11:55 AM   #15
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"Do you know what single function the convex follower performs that the flat follower doesn't? It's more of a band-aid that compensates for a lack of something than anything else...and that advantage is compromised by the use of an extended ejector, even if it doesn't touch it."
This is a good one,so going in reverse.The extended ejector flips the case out
sooner than the standard one so the convex follower works on the premise of
better support for the last round both during loading and extraction.
A convex follower would behave like a round still in the magazine so earlier ejection would minimize any support from below.

Last edited by polyphemus; January 25, 2013 at 12:13 PM. Reason: typo
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Old January 25, 2013, 12:04 PM   #16
polyphemus
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Now a little pontificating,because I only shoot exclusively 230 grain FMJ ball ammunition I have no use for anything other than classic 7R. GI magazines.
The only allowance to that is extra power springs,I like them.Thank you
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Old January 25, 2013, 01:37 PM   #17
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re:

Quote:
The extended ejector flips the case out
sooner than the standard one so the convex follower works on the premise of
better support for the last round both during loading and extraction.
A convex follower would behave like a round still in the magazine so earlier ejection would minimize any support from below.
Correct on the ejection part. It keeps the round from striking the ejector at a different angle than when it has a round under it for support. Not needed with proper extractor prep and function.,

Feeding, it makes no difference. Since an extended ejector is hit by the case before the slide uncovers the magazine, the pistol loses the function of the last round popping up and giving the case a little booster toward the port.

Quote:
GI magazines.
The only allowance to that is extra power springs,I like them.Thank you
Wolff's 11-pound/7-round springs are standard equipment around here. Both CMI and Metalform will install them on new magazines for a nominal extra cost. At last check, around a buck-fifty...which is cheaper than I can order'em from Brownells, even with my gunsmith's discount.
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