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Thread: Malfunction Clinic

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  1. #1
    Join Date
    1st June 2004
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    Lexington, North Carolina...or
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    Malfunction Clinic

    John asked me to write up a list of the most common/most likely malfunctions with the 1911 pistol. This will basically be no more than a compilation of what's already been covered in various threads and posts...but it'll be in one place, which will negate having to search through a gazillion lines in order to find an answer. Since this list can get pretty involved and lengthy in each description, it will be necessary to begin a new post for each description. I'll ask everybody to hold comments until it's done, for the sake of a smooth flow.

    Most functional problems with the 1911 platform are simple. Can't remember how many times I've written that. It was true in 1912, and it's true today. Most malfunctions are also simple to cure. The trick is in figuring out whether we have one of those problems that falls into the simple category, and which fall on the Hair-Pullin'/Head-Bangin' side of the page.

    The Failure to Feed:

    This one seems to plague 1911 aficianados more than any other single complaint. First, we have to determine exactly what a failure to feed is. Some pistols have a stoppage in which the round is partially chambered with the slide held out of full battery to varying degrees. This is not a failure to feed, although it's often used to describe the malfunction. "Jam" is another nondescript term that indicaes the pistol incurred a stoppage...but IS nondescript. True jams are pretty rare. It's most often a simple stoppage that can be cleared quickly, while jams are more labor/time intensive.

    If the round doesn't make it to the chamber...it's a failure to feed. If it gets into the chamber...even a little...it's a failure to go to/return to battery. Know the difference.

    Most failures to feed are caused by the magazine, assuming an in-spec feed and barrel ramp. The most common of failures to feed is the good old "Nose-Dive" into the feed ramp. This is a magazine issue in 99.9% of the instances. Specifcally, a magazine SPRING issue, especially if seen most often on the top round or two in the magazine. If it occurs as the magazine's capacity drops...say, on the last 2-3 rounds...it's most likely the follower angle, or a combination of both.

    The second most-often seen FTF is the Bolt-Over Base failure. Sometimes referred to as the "Rideover Failure to Feed" the two terms...like failure to feed and failure to go to battery...aren't the same. The BOB FTF usually produces a live-round stovepipe, with the bullet nose pointing skyward, and the side of the case caught between the slide and barrel hood. This can have varying degrees of cartridge exposed above the breechface...from bullet just a little above...to nearly the whole round standing tall, with the case pinched near the rim. The full "Rideover FTF" is a whole 'nother smoke. The BOB FTF is quick and easy to clear. The RO FTF will very often produce a true jam. In both malfunctions, the magazine spring is most often the cause, with a damaged or malformed magazine body running a close second.

    Next on the list of causes is the feed ramp angle. This angle is correctly closely held in both dimension and tolerance. 31 degrees is ideal, with a + 30 minute (half degree) minus zero.

    The feed ramp should be fairly smooth, with no deep toolmarks or defects that could "bite" into the bullet material and cause it to hang up. The feed ramp geometry is critical..though if a little out of spec, it can be compensated in most cases. Generally speaking, it's better for the ramp to be a little steep than a little shallow. Or...another way...30 degrees is better than 32. The steeper angle allows for the ramp to be altered a bit, while too shallow doesn't. You can always take a little material off...but it's tough to add material.

    The ramp should be cleanly contoured, with a distinct corner at the top. Here is where the average kitchen-table tinkerer gets into trouble by polishing the feed ramp. If he destroys that corner..which he often does, either by accident or intentionally...it accomplishes the same thing as having a too-shallow ramp. Namely, it directs the bullet nose into the barrel ramp...producing the maddening 3-Point Jam. When that happens, our Dremel Jockey...not realizing that his work has caused the problem...redoubles his efforts and polishes more aggressively. Then...seeing no positive results...turns his attention to the barrel ramp. It goes downhill from there. He may well get the gun to feed, but he will very likely lose critical case head support in the process, with bulged or even blown cases as a distinct possibility.

    Suspect the magazine FIRST. Don't cut, file, grind, sand, lap, or polish anything until you've eliminated the first suspect...and even then...don't do it until you've explored other possibilities.

    Some failures to feed are the fault of the extractor. Few...but still possible...and remember that...just because a magazine is new...that's no guarantee that it's good. There are a good many high-quality magazines around that...even though they work well in many pistols...often don't do so well in others. Every magazine marketer has his or her own ideas as to what's best as far as lip design and release timing is concerned...and there are very often subtle differences that escape the notice of those who don't understand what to look for. Very often, the cure will lie in one of these subtle differences. I've seen it happen just like that more times than I can remember...and I've "fixed" more pistols with a good magazine than I have by any other single exercise. From "Jammin' Jenny" to "Timex Watch" with a 20-dollar magazine.

    As in the medical profession...If you can cure the patient without surgery, it's better to do that than to start cuttin' on him just to see if it helps.


  2. #2
    Join Date
    1st June 2004
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    Lexington, North Carolina...or
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    Return to Battery

    Second in the series of most common malfunctions is the Failure to Go To...or Failure to Return to Battery. Actually more common then the true failure to feed, and sometimes a little more difficult to cure...though still not beyond the reach of the average tweaker. Most often due to excessive stem bind, it can also be a light 3-Point Jam. The 3-Point often mimics excessive stem bind, and is sometimes difficult to tell whether it's a light 3-Point, or excessive stem bind.

    Due to the feeding angles and other areas of the design, Browning-based tilt barrel designs operate under a certain amount of stem bind. Nature of the beast, and there's a purpose for it. It serves as a sort of brake that keeps the slide from slamming into battery so hard that it damages the lower lug feet...the slidestop crosspin...the slidestop pin's hole in the frame...or even the frame itself. Additionally, a proper measure of stem bind contributes to the overall control part of "Controlled Feed" that helps to make the 1911 and other similar designs so reliable. Excessive stem binding is another matter, and usually produces the failure to go to/return to battery sooner rather than later. All may be well until the gun gets a little too dirty, or a little too dry...or the recoil spring starts to fatigue a bit. Again, here is where many people decide to do a little reliability work...and reach for the ever-present and dreaded Dremel tool. Notice a trend here? Lay the Dremel on the table and leave it there!

    While the full-blown 3-Point Jam comes as a result of a wedging action, caused by hard interference brought on by barrel engagement timing...the stem bind problem is more of a friction and/or clearance issue. The most common being a simple matter of excessive extractor tension, and...almost evenly divided...extractor geometry. Trailing the possibilities in a distant third place is the magazine itself, though the magazine-related problem is seldom alone in the game...and when it is...it's generally our old friend, insufficient spring strength.

    Part of the magazine's function is in pushing the case rim under the extractor. In some magazine designs, it's ALL that performs this function, except for the final dab of pickup just as the round completes its breakover and enters the chamber. In others...notably the gradual, late release designs...the round breaking over to horizontal by way of the slide's forward movement utilizes the top of the barrel ramp to help cam it into the extractor. Although these magazines are timed for a later release...the release actually starts earlier, with the final release occurring later.

    Both functions are important...but with some magazines, the spring is THE deciding factor. In these, the ability of the case rim to smoothly cam the extractor open and allow access is critical. Not only is a light bevel at the bottom of the tensioning wall needed, but the positioning of the wall itself relative to the breechface can make or break reliable feeding. Here is where aftermarket extractors with oversized front pads...aka "Fitting Pad" comes into the picture. It allows the installer to set the extractor at the optimum depth...closer to or further away from the breechface center. This has two distinct advantages. It allows the use of abrupt/early release magazine timing and it allows the extractor to have a little heavier bend...and more tension for reliable extraction with less risk of the claw slipping off the case rim. Of course, the depth and added tension can also be used with gradual/late release magazines. So...There is a distinct advantage to a good aftermarket extractor, as long as the installer understands that they are NOT drop-in parts that only require tensioning in order to fundtion. They may...but probably not, and in any case, very unlikely to perform at optimum unless fitted and carefully tuned. Certain modifications are also often required.

    The distance between the two small, parallel blocks at the underside of the breechface are next on the list of probably causes. This distance should be no less than .484 inch, with .488 being the other end of the spectrum, though there are many smiths who will open'em up to .490 and beyond. But, for all but the most stubborn...this range will work. I like to see it about in the middle at .486 inch, with a light bevel on the lower corners to effect a funnel or camming effect. Seems to work well, and it's a lot easier than opening up the whole block.

    Next is roughness...either in the chamber...on the barrel ramp's top corner...or the breechface itself. Breechface finish problems are most often around the firing pin port, but can come in other ways and in other areas. There's no need to mirror polish the breechface...and like overpolishing the feed ramp...can be detrimental in some pistols. Most notably those that don't have the correct 89 degree/8 minute angle. If the breechface is closer to 90 degrees than specified, overpolishing of the breechface often results in loss of control of the feeding round, and most often near the bottom two rounds in the magazine...and most often on the last round.
    That angle is there to act as a soft brake that prevents the rim from jumping out of the magazine too quickly. If the angle is too close to dead vertical, it makes this little trick more likely to happen. So...If roughness of the breechface is noticed, the key word is "Smooth" rather than "Mirror." There is correctly and properly a small amount of friction offered to the upward moving rim. If it jumps, it's out of control. Loss of full control...even for a fraction of a second...is enough to make a malfunction more likely. Not guaranteed, and certainly not every time...but a matter of "Sooner or Later." A smooth, controlled transition from magazine to extractor pickup to breakover to seated in the chamber is the desideratum.

    Last on the list is the recoil spring itself. Technically and more correctly referred to as the "Action Spring" rather than the recoil spring...an overly-weak spring can be a contributor to a failure to go to battery...though seldom the only cause. In a pistol that is functioning correctly...even a half-strength spring should strip and chamber the round, and put the slide into full battery...provided that the spring is full-length and not cut too short. This isn't to suggest that the proper cure for an occasional failure to go to battery is to install a stronger than specified recoil spring...but rather that new, standard-strength spring should be included in an overall reliability tune-up. Changing the spring at regular intervals is the accepted practice that keeps the gun running smoothly, but isn't a cure-all for feed and RTB issues.

    The definitive test to determine if the extractor is the primary or sole cause of a failure to go to battery is simply to remove it and see if the gun functions more smoothly without it. If it does...the main problem is with the extractor. If not...it's elsewhere. One final point is that...although the extractor is the primary cause...there may also be other factors at work along with the extractor issues. A stacking of sorts where no single problem will cause the problem by itself...work together to throw everythig oput of whack. While dddressing any one of these problems may allow the gun to work...seeing to all of them provides a higher degree of reliability than addressing only one or two. The quintessential "Reliability Job" that is usually done, but sometimes overdone. Not always to the point of producing diminishing returns...but unnecessary work to no real or practical end. i.e. If it functions at or near 100%...what can really be done to make it more reliable? Since it's statistically impossible to improve on 100%, and since 100% is a statistical impossibility...what can be done to increase the odds of near-perfect function than simply seeing to simple details? The answer is, of course...Nothing.

    The more that you alter the basic dimensions beyond a certain point...the greater the liklihood of taking it too far. Simply put...While a little is good...a lot isn't necessarily gooder. Know when to stop.

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