Welcome to M1911.ORG
The M1911 Pistols Organization Forums Site


Dear members,
Please make sure the email address we have for you, is correct and valid.


Sponsors Panel
If you intend to buy something from the companies advertising above, or near the bottom of our pages, please use their banners in our sites. Whatever you buy from them, using those banners, gives us a small commission, which helps us keep these sites alive. You still pay the normal price, our commission comes from their profit, so you have nothing to lose, while we have something to gain. Your help is appreciated.
If you want to become a sponsor and see your banner in the above panel, click here to contact us.

Page 1 of 2 12 LastLast
Results 1 to 10 of 15

Thread: Trying to get a better understanding of how 1911 magazines work

  1. #1

    Trying to get a better understanding of how 1911 magazines work

    A member of the Bullseye Forum suggested I read this thread:

    http://how-i-did-it.org/magazines2/read-my-lips.html

    While starting to read that thread, the author suggested I read this thread first:

    http://how-i-did-it.org/magazines2/read-my-lips.html

    I no sooner started to read this articele, when it suggested ""Before continuing on, please read this post on controlled feed principles on the M1911.org forum."
    I ended up in this thread, in this forum:

    https://forum.m1911.org/showthread.p...eed-Principles



    Does anyone here know of an even simpler starting point, to read (or preferably watch) something written for beginners, to understand the last link I posted up above? I was doing fine until I reached "The bullet ogive is also important. The angles have to work together in order for the controlled feed to function as intended. Bullet length forward of full diameter is also important. If the cartridge is too far forward in the magazine when it hits the ramp, full control is compromised...or lost........" I can, and will, search for what the "ogive" is, but from that point on, I'm lost. Illustrations would be very helpful.


    I suspect that this is getting much too technical to discuss on the Bullseye Forum, and I'm concerned that people here may feel I'm too ignorant to get through the process of understanding what these articles discuss.

  2. #2
    Join Date
    21st September 2008
    Posts
    9,962
    Posts liked by others
    199
    Simply put, the ogive is the profile of the bullet, i.e. the exact nature of the curvature from the mouth of the case, all the way to the front. Two cartridges could have the same overall length and "ball"-profile bullets, but one could be tapering a bit early, looking "pointier", the other could start tapering slowly, then curve inwards more sharply, closer to the tip.

    I hope this makes some sense.
    Too many people miss the silver lining because they're expecting gold.
    M. Setter

  3. #3
    Sure does, thank you. In my case, I'm shooting SWC ammo, so I don't see how "ogive" would relate to rounded bullets, but that's only the start. As the article continues, I haven't been able to follow things.

    Are there any illustrations posted here or elsewhere, that show how the cartridges get from the magazine to the barrel, and the various steps as that happens?

    I could ask individual questions, one at a time, as I work my way through this, but a few illustrations might answer everything I need to understand.

  4. #4
    Here are the things I'm still wondering about:

    The corner at the top of the feed ramp also must not be altered except when correcting the feed ramp angle. If the cartridge isn't deflected upward into the barrel ramp...often mistakenly referred to as the "Barrel Throat"...at a steep enough angle, it strikes the barrel ramp too low.

    When it does that, it pushes the barrel forward...and when the barrel moves forward too early, it also cams UP too early. This increases the angle of cartridge entry and brings about the well-known Three-Point Jam. A too-long link has the same effect, but with different mechanics.

    If the round hits the barrel ramp above center, it works to keep the barrel down against the frame bed, keeping the angle correct for the horizontal break-over and chambering. Once the cartridge is horizontal, or neraly so, and deep into the chamber, the barrel is free to cam into
    lockup. The noted gap between the lower edge of the barrel ramp and top corner of the frame ramp helps to insure that the cartridge will enter the barrel ramp above centerline and well forward of the corner. This is also an aid to keeping the barrel down in the bed during the initial feeding phase.

    The angled approach is also a requirement for the rim to get under the extractor correctly. If the feed angle is reduced...straightened out, as some are fond of saying...the bottom corner of the extractor hook is positioned very close to the rear face of the rim. A small variation in case rim can make contact there, and cause a stoppage.

    Until now, I was told that if the extractor is too long, that is what causes it to make contact with the case, and potentially dent the case.
    When I test the extractor to see if it grips the round properly, the round is perfectly level as I do this.
    Are you guys saying that if the round is at a slight angle, it makes it easier for the round to position itself properly with the extractor?


    Lightly radiusing the bottom corner of the extractor hook nose is done to provide a little extra clearance there...for the reason of varying case rim diameters...but it won't take care of an incorrect feed angle. The angled ramp insures that the rim approaches the hook from well underneath.

    I don't see what the problem would be, if the horizontal round slipped into the extractor, but I can understand this part of the write-up.

    Okay...the cartridge is deflected up into the chamber. The forward radius of the bullet ogive is in contact with the roof of the chamber...but what it that cartridge is not only too short, but the ogive is also too wide. The short cartridge moves farther out of the magazine when it takes its necessary dive. That makes the dive steeper, and the resulting upward delfection is also steeper. The bullet ogive hits the chamber roof farther back and at a steeper angle...and you have another variation of the Three-Point Jam...except this one is jammed tighter. In extreme cases, this one can almost mimic the Bolt-Over Base failure to feed.

    I think this is what is happening when my short Magnus #801 bullets go into the barrel of my Baer Premiere II. I'm guessing that the write-up is saying that the bullet needs to contact the chamber further away, rather than closer. Is this ti keep the cartridge at the correct angle, so it doesn't "jam up" and lock in place? Just guessing, but that's what I think the article is saying....

    Positive magazine control of the round depends largely on spring tension. This isn't an issue when the magazine is past half-full, but as the magazine loses rounds, the tension degrades. Most important in controlling the last round...when spring loading is at a minimum...it requires a helping hand to prevent the last round from moving too far forward and possibly escaping
    under the inertial effects of recoil, which...in a .45 caliber 1911...is a pretty violent, slam-bang affair.

    Most of the jams I got were with rounds at the lower part of the magazine, but when I tested this in my apartment, with dummy rounds, all of the Magnus #801 rounds locked up. It didn't matter where they were in the magazine.

    That helping hand comes in the form of a tiny little bump on top of the magazine follower.

    I am looking at my magazines from Springfield, Baer, and Wilson. None of them have anything that looks like a tiny little bump.


    Without it, the cartridge is free to roam...and often does. It may not cause a stoppage if it moves too far forward...even if it doesn't completely escape...but it feeds at a straighter angle, which...as we've already covered...isn't good. It's not good for reliability and it;s not good for the extractor.

    I'm lost here. No idea what this is describing.


    The extractor wasn't designed to snap over the rim...not even the external extractors. The externals are simply more tolerant of the occurrence, but they'll still suffer damage if forced to do it for very long. At the least, the coil springs that drive them will
    weaken much faster because they're being compressed farther than they're supposed to. Some may even compress enough to go into coil bind...which damages a coil spring quickly.

    Why would the extractor be snapping over the rim? I assume the rim is pushed up against the extractor, just like when I did this by hand, and the rim just naturally goes "into" the opening in the extractor. I can't visualize what is being described here.


    I doubt anyone has ever made such an illustration, but a slow motion video could show each of these things happening.

    The best I could find was this:
    https://www.youtube.com/watch?v=EjQrhDKDWFk

    At 1 minute, 47 seconds in, it shows how rounds are loaded into a 1911.
    It shows how the round is pushed forward into the feed ramp, and then into the barrel.
    Unfortunately, it doesn't show how the rounds get under the extractor, or what parts of the barrel/chamber the bullet touches as it goes into the chamber.

    Since everything is shown to scale, I *do* see what part of the round head bullet hits the feed ramp/barrel, but everything would be different with a SWC, worse yet with a flat end wadcutter.

    Maybe someone here can use this snapshot as a reference, and explain how the cartridge is controlled:
    Screen Shot 2020-08-09 at 14.37.18.jpg

  5. #5
    I should add that starting with the image I just posted, long before the top of the bullet is going to touch the top of the chamber, it needs to "hit" the feed ramp, and then the lower part of the chamber, which will presumably get the bullet on its way into the chamber. I now understand how the magazine will control the position of the cartridge as it's going into the chamber.

    This is shown at 2:30 into the video, presumably to scale.

    It would be great if this video could be edited to show the path of the cartridge, based on the possible configurations of the magazine..... :-)

    Watch the video again, and set the playback speed to 1/4. That way everything can be seen more clearly.

    One more snapshot:

    Screen Shot 2020-08-09 at 14.53.38.jpg
    Last edited by mikemyers; 9th August 2020 at 13:57.


  6. #6
    Join Date
    25th September 2006
    Location
    South of Lake Superior
    Posts
    13,994
    Posts liked by others
    99
    Quote Originally Posted by mikemyers View Post
    Until now, I was told that if the extractor is too long, that is what causes it to make contact with the case, and potentially dent the case.
    Everybody does seem to get their panties all in a wad over this, but many don't realize such contact will occur in a mid-spec Government Model. My wadcutter gun has 10's of thousands of rounds through it with such contact and resulting case dents and it doesn't bother me, the gun or the ammunition at all. Gun's had the same extractor since the early 1960's. Extractor's still OK and the dents in the case extraction groove don't affect a thing - I reload them until I lose them.
    When I test the extractor to see if it grips the round properly, the round is perfectly level as I do this.
    Are you guys saying that if the round is at a slight angle, it makes it easier for the round to position itself properly with the extractor.
    Not me. If you think about how the case rim gets up into contact with the extractor nose, the case angle is essentially fixed by the design of the gun and there's little or nothing that can be done to change it.
    I don't see what the problem would be, if the horizontal round slipped into the extractor, but I can understand this part of the write-up.
    If you'll look at 4:32 of the video you'll see that if the round is horizontal it is already under the control of the extractor (or if not is getting in the process of being push fed).
    I think this is what is happening when my short Magnus #801 bullets go into the barrel of my Baer Premiere II. I'm guessing that the write-up is saying that the bullet needs to contact the chamber further away, rather than closer. Is this ti keep the cartridge at the correct angle, so it doesn't "jam up" and lock in place? Just guessing, but that's what I think the article is saying...
    I don't understand what the article is saying either unless the writer is hypothesizing why SWCs can be hard to feed.
    Most of the jams I got were with rounds at the lower part of the magazine, but when I tested this in my apartment, with dummy rounds, all of the Magnus #801 rounds locked up. It didn't matter where they were in the magazine. I am looking at my magazines from Springfield, Baer, and Wilson. None of them have anything that looks like a tiny little bump.
    That little bump is part of an Ordnance spec'd magazine follower.
    I'm lost here. No idea what this is describing.
    Why would the extractor be snapping over the rim? I assume the rim is pushed up against the extractor, just like when I did this by hand, and the rim just naturally goes "into" the opening in the extractor. I can't visualize what is being described here.
    What's being described is a push feed, a situation where the case rim gets ahead of the extractor instead of sliding up along the breechface. The forward moving slide and extractor will chamber the round and then the inertia of the slide will cause the extractor claw to snap over the case rim. Many claim push feeds will bring about an Earth-ending apocalypse but fail to realize many guns push feed and the shooter never knows it: the gun goes BANG!; the brass is never examined or even if it's reloaded, the little marks left by the push feed on the case rim are never noticed (they don't affect reloading at all).

    One important false impression left by the video is that all cartridges from the magazine feed the same way - specifically their attitude (angle) when making first contact with the frame feed ramp or the barrel ramp.
    • The first round out of any full magazine will make first contact down the lowest on the frame feed ramp
    • The last round out of any magazine may not even hit the frame feed ramp - and strike only the barrel ramp.

    P(10)3211234d These Boo(li)ts Are Made For Walkin'..., Post 1 .jpg

    So your gun jams, huh? Try this little experiment based solely on a hunch of mine:
    • Assemble your Les Baer without its firing pin and lock its slide back
    • Measure and record the overall length (COAL) of one of your reloads.
    • Load this as the top round in a full magazine.
    • Insert this magazine and slingshot the slide closed.
    • Carefully pull back the slide with the gun on its right side and extract that unfired round into a rag
    • Re-measure the COAL of that extracted round and a find out how much shorter it got just from chambering

    Q: How much shorter did it get?
    When you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind. [Lord Kelvin]
    Last edited by niemi24s; 11th August 2020 at 10:14.


  7. #7
    Join Date
    2nd June 2004
    Location
    Terra
    Posts
    21,857
    Posts liked by others
    671
    Quote Originally Posted by mikemyers View Post
    Lightly radiusing the bottom corner of the extractor hook nose is done to provide a little extra clearance there...for the reason of varying case rim diameters...but it won't take care of an incorrect feed angle. The angled ramp insures that the rim approaches the hook from well underneath.
    The radius (actually, there are a couple of places on the extractior that should be radiused) is for smoother feeding, not clearance.


    Positive magazine control of the round depends largely on spring tension. This isn't an issue when the magazine is past half-full, but as the magazine loses rounds, the tension degrades. Most important in controlling the last round...when spring loading is at a minimum...it requires a helping hand to prevent the last round from moving too far forward and possibly escaping under the inertial effects of recoil, which...in a .45 caliber 1911...is a pretty violent, slam-bang affair.
    The magazine doesn't control the round during feeding -- the extractor does. The magazine's job is to feed the round. They work together.


    The extractor wasn't designed to snap over the rim...not even the external extractors. The externals are simply more tolerant of the occurrence, but they'll still suffer damage if forced to do it for very long. At the least, the coil springs that drive them will
    weaken much faster because they're being compressed farther than they're supposed to. Some may even compress enough to go into coil bind...which damages a coil spring quickly.

    Why would the extractor be snapping over the rim? I assume the rim is pushed up against the extractor, just like when I did this by hand, and the rim just naturally goes "into" the opening in the extractor. I can't visualize what is being described here.
    The extractor snaps over the rim because the timing is off and the round jumps free of the magazine before the case rim can be captured. When this happens you no longer have controlled feed -- you now have an uncontrolled push feed, in which the extractor pushes the round into the chamber rather than the breechface.


    I doubt anyone has ever made such an illustration, but a slow motion video could show each of these things happening.


    Maybe someone here can use this snapshot as a reference, and explain how the cartridge is controlled:
    Screen Shot 2020-08-09 at 14.37.18.jpg
    1911Tuner did an excellent explanation/description of how the 1911 controlled feed works, several years ago. At this point, I don't remember if it's a post in the 'Gunsmithing and Troubleshooting" discussion area, or if got archived in one of the technical articles on our Home Page site.
    Hawkmoon
    On a good day, can hit the broad side of a barn ... from the inside

  8. #8
    Quote Originally Posted by niemi24s View Post
    ......One important false impression left by the video is that all cartridges from the magazine feed the same way - specifically their attitude (angle) when making first contact with the frame feed ramp or the barrel ramp.
    • The first round out of any full magazine will make first contact down the lowest on the frame feed ramp
    • The last round out of any magazine may not even hit the frame feed ramp - and strike only the barrel ramp.

    ........
    Thank you for such good explanations.

    When I read the above text, it explains a photo I took of my Baer earlier this evening.
    This is the result of having tried to cycle dummy rounds with a Magnus #801 bullet:

    IMG_3012.jpg

    Is this because the magazine spring pressure is decreasing as round after round cycles through the gun?

    Good thing I didn't clean the gun before taking the photo.
    Last edited by mikemyers; 10th August 2020 at 22:51.


  9. #9
    Quote Originally Posted by Hawkmoon View Post
    ...........1911Tuner did an excellent explanation/description of how the 1911 controlled feed works, several years ago. At this point, I don't remember if it's a post in the 'Gunsmithing and Troubleshooting" discussion area, or if got archived in one of the technical articles on our Home Page site.......
    Is this the article you are referring to? https://rangehot.com/1911-controlled-feed/

  10. #10
    Join Date
    25th September 2006
    Location
    South of Lake Superior
    Posts
    13,994
    Posts liked by others
    99
    Army Ordnance blueprints for all of the Government Model parts can be found in our Tech Issues section, including the extractor. While there's no reason any extractor made to these specifications won't do its job, it's kind of hard to see what its forward end looks like because of the small size of the drawing. What follows is a clearer depiction of one based on those specifications:

    P(09)3170002extracta2.jpg

    As with most other 1911 parts, every Tom, Dick and Harry seems to have their own favorite idea of what a good extractor should be like. I prefer one shaped as shown. Note the radii at D, F & G which any good extractor needs for proper capture of the ascending case rim. BTW, here's a mug shot of an extractor doing what any mid-spec one will do in an in-spec gun:

    P(10)3170001c Oh Mama....I Need Help With A Llama, Post 14.jpg

    • Does it make a little dent in the case extraction groove? Sure!
    • Do I care?

    When you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind. [Lord Kelvin]
    Last edited by niemi24s; 11th August 2020 at 10:03.


Page 1 of 2 12 LastLast

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  



Sponsors Panel
If you intend to buy something from Brownells, please use their banners above. Whatever you buy from them, gives us a small commission, which helps us keep these sites alive. You still pay the normal price, our commission comes from their profit, so you have nothing to lose, while we have something to gain. Your help is appreciated.
If you want to become a sponsor and see your banner in the above panel, click here to contact us.

Non-gun-related supporters.
Thank you for visiting our supporters.