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12-05-2007, 11:20 PM
Editors Note: The original article has been split into 3 parts.
Part I of III of the 1911 Magazine Anaylsis series.
1911 Magazine Analysis
http://230grain.com/images/articles/magazines/img/mag_group_photo.jpg
[Introduction]
I recently got the opportunity to look at a selection of 1911 magazines. Alas, my good fortune came at another's expense: A friend of mine noticed a burr developing in the slidelock notch of his Para-Ordnance SSP along with some wear along the front side of the slide's slidestop cutaway after less than a thousand rounds. My friend returned the gun to Para-Ordnance for service, only to have it sent back with the burrs lightly dressed and a note saying that his warranty did not cover "normal wear," but they would not charge return shipping "in the interests of customer service." This is definitely not the behavior of a correctly-functioning 1911, but since help was clearly not going to come from Para-Ordnance, my opinion was requested. (Clearly an act of desparation.)
http://230grain.com/images/articles/magazines/img/tn_bite.jpg (http://230grain.com/images/articles/magazines/img/bite.jpg)
Houston, we have a problem.
After seeing the above photos, I opined that either his slide stop had a really sharp front edge to it and/or one of his magazines' followers was getting far too frisky with the slidelock's inner lug, forcing it up hard while the slide was still on its way back. Logic dictates that if all it takes to mangle is an overzealous follower, we'd see a lot more of these kinds of problems; maybe the heat-treating in this partcular slide is sub-par. Once you open the door to soft metal, though, it raises the possibility that any or all of the followers could play a part in the mangling process. There's also the chance that the slidelock could be getting bumped by a bullet on its way up enough to raise a ding, but not enough to induce premature slidelock; alternately, a thumbs-high hold hitting the slidelock could provide a similar bump from the outside. The only problems with these scenarios is that the burr's location looks pretty consistent and random bumps would have to happen with fairly high frequency to account for a ding like that. Of course, the follower theory would have less than 140 occurrences of aggressive follower rise resulting in a chewed up slide.
After hemming and hawing in this fashion for several minutes, I concluded that I couldn't say for sure without seeing the magazines. What was supposed to be a hypothetical became all too real: I got sent the mags, despite my protests that I couldn't guarantee a conclusive answer, a coherent analysis, or even the minimal level of competence required to avoid drooling on his magazines.
Truth be told, I was happy to be able to play with this wide a variety of mags. I've always been a staunch 1911 magazine traditionalist, which has limited my experience with the more varied examples of 1911 mags. My reasons for sticking with what many consider old-fashioned designs are good ones and I'll enumerate them later, but it would be worth the time to become familiar with other makes; maybe I'd even get lucky and have my assumptions proven wrong.
http://230grain.com/images/articles/magazines/img/tn_group_photo.jpg (http://230grain.com/images/articles/magazines/img/group_photo.jpg)
I love science.
So it was with great excitement and a dramatic photograph that I assembled the loaner magazines, a selection of mags from my own collection, and my trusty Mil-Spec to answer the following question: Is it possible that a magazine's follower is contributing to the slide peening, and what difference do all these different magazine designs make?
[Gross Anatomy]
I have the following brands of magazines to work with: Para-Ordnance, Metalform, Wilson Combat, Springfield Armory, Colt, another Metalform, and another Colt. (This is the order they appear in the first two photos on the page.)
http://230grain.com/images/articles/magazines/img/tn_lineup_angle.jpg (http://230grain.com/images/articles/magazines/img/lineup_angle.jpg)
The unusual suspects.
The Para-Ordnance is the OEM magazine included with the SSP. It uses a plastic follower with a groove on its forward section. The Metalform mag uses a rounded follower with an enclosed front, the kind often recommended to people with aluminum-framed 1911 who are worried about the traditional split follower gouging into the frame ramp. Third from the left is the famous (or infamous, depending on one's point of view) Wilson 47D, which uses a "self-lubricating" nylon follower with a deep channel cut in it. The middle mag is one I dug out of my range bag, a stainless steel Springfield Armory magazine that came with my Mil-Spec. It's the first of the magazines to use the traditional flat follower with a dimple on it and a bent lower leg. The Colt to its right looks similar on casual inspection, but the follower here is flat and bent in the back to form the lower section. We return to tradition with the second-to-last magazine, a Metalform that's pretty much the same as the Springfield in design, but much different in execution. (More on that later.) Finally, we have my newest acquisition, a Colt factory magazine. This mag uses yet another split, dimpled follower, but its feed lips are tapered instead of parallel. This kind of magazine is sometimes referred to as a hybrid magazine, and since "hybrid" is easier to type than "my new Colt magazine with tapered lips and a split follower, not to be confused with the other Colt magazine that has parallel lips and a flat follower", that's what I'm going to call it.
http://230grain.com/images/articles/magazines/img/tn_lineup_top.jpg (http://230grain.com/images/articles/magazines/img/lineup_top.jpg)
Which follower is the leader?
The first thing that jumped out at me when looking at these magazines was how different they all were. It's a trivial observation, but when you consider that every one is designed to do the same thing, the presence of so much variety should raise some flags. Follower construction uses metal or plastic to form dimpled, flat or recessed shapes that are then seated at different angles in the magazine bodies. The feed lips are strongly tapered, lightly tapered, or parallel, and feature release points that range from gentle flares to abrupt edges.
http://230grain.com/images/articles/magazines/img/tn_lineup_front_high.jpg (http://230grain.com/images/articles/magazines/img/lineup_front_high.jpg)
Left to right: Colt, Wilson, Metalform, Para, Colt hybrid, Springfield
The result of all this variety in the magazines' construction is corresponding variety in the way they present the top round. In the photo above, the magazines are all indexed by their mag catch slots to eliminate any variance due to magazine length, leaving only their own variances displayed. The highest cartridge angle award goes to the Colt hybrid second from the right; we can thank the tapered feed lips for that. The rounds that actually sit the highest are found in the Para mag directly to the left of the Colt hybrid, but the angle found here is lower than the hybrid's (probably because the groove in the front part of the follower lets the front of the cartridge sit lower). The Metalform with the rounded follower (third from the left) gets a higher angle than the Para, but the rounds don't sit as high up; in fact, it looks really similar to the Wilson on its left. Finally, there are the Colt with the flat follower and the Springfield (far left and right, respectively): These have similar feed lip construction (in fact, the Springfield's are more restrictive), but the Colt presents its rounds at a lower angle. My bet is that the Colt's follower doesn't support the front of the round as much.
These difference can and do affect the kinematics of feeding, but the question is to what extent this matters. Let's find out, shall we?
Part 2: Feeding time. (http://230grain.com/showthread.php?t=441)
(c) 2007 C. Kaukl - All Rights Reserved.
Reprinted with permission.
Part I of III of the 1911 Magazine Anaylsis series.
1911 Magazine Analysis
http://230grain.com/images/articles/magazines/img/mag_group_photo.jpg
[Introduction]
I recently got the opportunity to look at a selection of 1911 magazines. Alas, my good fortune came at another's expense: A friend of mine noticed a burr developing in the slidelock notch of his Para-Ordnance SSP along with some wear along the front side of the slide's slidestop cutaway after less than a thousand rounds. My friend returned the gun to Para-Ordnance for service, only to have it sent back with the burrs lightly dressed and a note saying that his warranty did not cover "normal wear," but they would not charge return shipping "in the interests of customer service." This is definitely not the behavior of a correctly-functioning 1911, but since help was clearly not going to come from Para-Ordnance, my opinion was requested. (Clearly an act of desparation.)
http://230grain.com/images/articles/magazines/img/tn_bite.jpg (http://230grain.com/images/articles/magazines/img/bite.jpg)
Houston, we have a problem.
After seeing the above photos, I opined that either his slide stop had a really sharp front edge to it and/or one of his magazines' followers was getting far too frisky with the slidelock's inner lug, forcing it up hard while the slide was still on its way back. Logic dictates that if all it takes to mangle is an overzealous follower, we'd see a lot more of these kinds of problems; maybe the heat-treating in this partcular slide is sub-par. Once you open the door to soft metal, though, it raises the possibility that any or all of the followers could play a part in the mangling process. There's also the chance that the slidelock could be getting bumped by a bullet on its way up enough to raise a ding, but not enough to induce premature slidelock; alternately, a thumbs-high hold hitting the slidelock could provide a similar bump from the outside. The only problems with these scenarios is that the burr's location looks pretty consistent and random bumps would have to happen with fairly high frequency to account for a ding like that. Of course, the follower theory would have less than 140 occurrences of aggressive follower rise resulting in a chewed up slide.
After hemming and hawing in this fashion for several minutes, I concluded that I couldn't say for sure without seeing the magazines. What was supposed to be a hypothetical became all too real: I got sent the mags, despite my protests that I couldn't guarantee a conclusive answer, a coherent analysis, or even the minimal level of competence required to avoid drooling on his magazines.
Truth be told, I was happy to be able to play with this wide a variety of mags. I've always been a staunch 1911 magazine traditionalist, which has limited my experience with the more varied examples of 1911 mags. My reasons for sticking with what many consider old-fashioned designs are good ones and I'll enumerate them later, but it would be worth the time to become familiar with other makes; maybe I'd even get lucky and have my assumptions proven wrong.
http://230grain.com/images/articles/magazines/img/tn_group_photo.jpg (http://230grain.com/images/articles/magazines/img/group_photo.jpg)
I love science.
So it was with great excitement and a dramatic photograph that I assembled the loaner magazines, a selection of mags from my own collection, and my trusty Mil-Spec to answer the following question: Is it possible that a magazine's follower is contributing to the slide peening, and what difference do all these different magazine designs make?
[Gross Anatomy]
I have the following brands of magazines to work with: Para-Ordnance, Metalform, Wilson Combat, Springfield Armory, Colt, another Metalform, and another Colt. (This is the order they appear in the first two photos on the page.)
http://230grain.com/images/articles/magazines/img/tn_lineup_angle.jpg (http://230grain.com/images/articles/magazines/img/lineup_angle.jpg)
The unusual suspects.
The Para-Ordnance is the OEM magazine included with the SSP. It uses a plastic follower with a groove on its forward section. The Metalform mag uses a rounded follower with an enclosed front, the kind often recommended to people with aluminum-framed 1911 who are worried about the traditional split follower gouging into the frame ramp. Third from the left is the famous (or infamous, depending on one's point of view) Wilson 47D, which uses a "self-lubricating" nylon follower with a deep channel cut in it. The middle mag is one I dug out of my range bag, a stainless steel Springfield Armory magazine that came with my Mil-Spec. It's the first of the magazines to use the traditional flat follower with a dimple on it and a bent lower leg. The Colt to its right looks similar on casual inspection, but the follower here is flat and bent in the back to form the lower section. We return to tradition with the second-to-last magazine, a Metalform that's pretty much the same as the Springfield in design, but much different in execution. (More on that later.) Finally, we have my newest acquisition, a Colt factory magazine. This mag uses yet another split, dimpled follower, but its feed lips are tapered instead of parallel. This kind of magazine is sometimes referred to as a hybrid magazine, and since "hybrid" is easier to type than "my new Colt magazine with tapered lips and a split follower, not to be confused with the other Colt magazine that has parallel lips and a flat follower", that's what I'm going to call it.
http://230grain.com/images/articles/magazines/img/tn_lineup_top.jpg (http://230grain.com/images/articles/magazines/img/lineup_top.jpg)
Which follower is the leader?
The first thing that jumped out at me when looking at these magazines was how different they all were. It's a trivial observation, but when you consider that every one is designed to do the same thing, the presence of so much variety should raise some flags. Follower construction uses metal or plastic to form dimpled, flat or recessed shapes that are then seated at different angles in the magazine bodies. The feed lips are strongly tapered, lightly tapered, or parallel, and feature release points that range from gentle flares to abrupt edges.
http://230grain.com/images/articles/magazines/img/tn_lineup_front_high.jpg (http://230grain.com/images/articles/magazines/img/lineup_front_high.jpg)
Left to right: Colt, Wilson, Metalform, Para, Colt hybrid, Springfield
The result of all this variety in the magazines' construction is corresponding variety in the way they present the top round. In the photo above, the magazines are all indexed by their mag catch slots to eliminate any variance due to magazine length, leaving only their own variances displayed. The highest cartridge angle award goes to the Colt hybrid second from the right; we can thank the tapered feed lips for that. The rounds that actually sit the highest are found in the Para mag directly to the left of the Colt hybrid, but the angle found here is lower than the hybrid's (probably because the groove in the front part of the follower lets the front of the cartridge sit lower). The Metalform with the rounded follower (third from the left) gets a higher angle than the Para, but the rounds don't sit as high up; in fact, it looks really similar to the Wilson on its left. Finally, there are the Colt with the flat follower and the Springfield (far left and right, respectively): These have similar feed lip construction (in fact, the Springfield's are more restrictive), but the Colt presents its rounds at a lower angle. My bet is that the Colt's follower doesn't support the front of the round as much.
These difference can and do affect the kinematics of feeding, but the question is to what extent this matters. Let's find out, shall we?
Part 2: Feeding time. (http://230grain.com/showthread.php?t=441)
(c) 2007 C. Kaukl - All Rights Reserved.
Reprinted with permission.