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Gunsmithing Information

Smokestack myths

by Les Bengtson

One of the enduring myths about the Colt 1911 series pistols is that there is a malfunction, termed a smoke stack, that is caused by "limp wristing". It is true that the 1911, and some other pistols, will sometimes have an ejection problem where the fired case fails to fully eject and is partially caught in the ejection port looking like a smoke stack sticking up. That this problem is cause by a "limp wrist" is where we enter the realm of mythology. The problem with myths is that we take them a face value and do not attempt to examine the logic behind them. In other words, we do not try to determine, by empiric experiment, whether the myth is true. In this article I will explore the smoke stack-limp wrist myth, explain the tests I have performed to determine its truth and offer some possible explanations for why this malfunction may occur.

The myth of the smoke stack malfunction being caused by the shooter having a "limp wrist" has been around for years. You will see it published in magazine articles and columns. When I was teaching at Gunsite many years ago, one of my fellow instructors told a student that he was holding is pistol limply, resulting in a series of smoke stack malfunctions. By holding the pistol more firmly, the student was able to cut down on the number of malfunctions, but not eliminate them entirely. If the folk lore surrounding the limp wrist is true, we need to teach shooters to take a stronger grip on the pistols. If, however, as I believe, this is an equipment related malfunction, the strongest of grips will not eliminate the problem. Furthermore, by defining this as a shooter, rather than an equipment, problem we prevent the shooter from seeking help that would correct the problem. This last facet is the most troubling, since the majority of 1911s are used as competition and self defense pistols. The individual who looses a match because of a preventable problem is chagrined. The individual who looses a gunfight because of a preventable problem is either dead or seriously injured. Thus, it would seem that an scientific investigation of this problem is long overdue.

When I attended my first Gunsite class in 1979, Jeff Cooper demonstrated the controllability of the .45 auto by holding it with only his thumb and trigger finger and firing it. Several years later, when I attended the first Provost Instructor's workshop, each of us was required to demonstrate the same maneuver so that we could demonstrate it to our students. I was impressed by the fact that, in spite of this rather insecure hold on the pistol, none of the instructor's pistols smoke stacked! This, I thought, might be the empirical test that will determine whether the smoke stack is caused by failing to hold the pistol tightly enough or whether some mechanical failure is involved. I decided to do some further testing.

I decided to use one of my "Advanced Tactical Class" pistols for this test series. This pistol has never smoke stacked in several years of practice and competition use. If smoke stack malfunctions are caused by a limp wrist or other form of loose holding, this pistol should begin to show this malfunction when loosely held on only two fingers. Thus, the basic experiment was born. Two other areas needed to be decided on--the number of rounds to be fired and whether the pistol should be fired with an empty magazine and a round in the chamber or whether the pistol should be fired with a fully loaded magazine.

The smallest sample size that is statistically significant is three. The largest sample size is infinite. I have never seen a pistol that would smoke stack on every round. Most pistols exhibiting this problem will only have this form of malfunction once or twice in a match consisting of 50-100 rounds. With this in mind, I decided to perform three tests of 50 rounds each and record the number of smoke stack malfunctions (if any) for each test series.

The second question was whether to: a) load only a single round and allow the slide to lock back with each shot, b) to shoot using loaded magazines and only allow the slide to lock back on the last shot from a full magazine, or c) to shoot from loaded magazines and replace each magazine with a fresh one prior to firing the last shot from the magazine. I decided on the last alternative. By allowing the slide to lock back we are introducing another variable. The cycle of the slide is different when the magazine is empty. When chambering a round from the magazine, the slide actually strikes the ejected case as the slide moves forward. Thus, the different slide cycling of the last round with an empty magazine in the gun, might cause us to reach an erroneous conclusion if the entire test series was composed of this style of shooting.

The tests were performed on three different days, each day firing 50 rounds and recording the number of smoke stacks which occurred. The pistol was then cleaned and lubricated prior to the next range session. For the first two tests, the ammunition was the H & G 68 lead SWC bullet loaded to make IPSC major classification. This is similar to the load used by most competitors and, hence, the one used most commonly when smoke stacks occur. The third test series used a 230 grain lead round nosed bullet loaded to the published factory velocity of 830 fps to find out whether the slightly greater recoil of this load would affect the tests.


The tests were conducted over three range sessions, two of them in front of witnesses. As the photos show, the pistol was held with only the thumb and trigger finger of the shooting hand. Magazines were changed when empty, leaving a round in the chamber. The last round of each test series (round 50) was fired with an empty magazine in the pistol and the slide allowed to lock back to see whether the test results would vary as a function of being the last round in the pistol. THERE WERE NO SMOKE STACK MALFUNCTIONS DURING THE TEST SERIES. The only problem encountered was that holding the pistol with only thumb and fore finger for 50 rounds caused my hand to start cramping, probably resulting in the few shots outside of the general group. The only other thing learned by this test is that you can really fire a fairly good group this way--at least at seven yards.


If, as the test results seem to indicate, the tendency of the 1911 .45 auto to have smoke stack malfunctions is not caused by the lack of a firm hold on the pistol then there must be an equipment, hence mechanical, cause. Unfortunately, since this problem has previously been defined as a shooter, not a firearm, problem, the number of samples brought into my shop for repair has been limited. I have, over the last thirty years, owned a large number of .45s, some of which have exhibited a smoke stacking problem. By combining these two small samples some conclusions may be drawn.

First, every pistol I have examined that had a problem with smoke stacking had both a weak extractor and a loose ejector. When a pistol comes into the shop, and each time I clean my personal pistols, after I remove the slide I try to wiggle the ejector. If it moves it needs attention. It can be replaced (best solution) or it can be removed, the ejector and frame degreased and then reassembled using an epoxy compound (Brownell's Acra-Weld or JB Weld). Either method will produce a tight ejector. The extractor should be a tight fit in the extractor tunnel in the slide. Make sure that you thoroughly clean the extractor tunnel before checking the extractor tension. I have found that extractor tension is far less critical than some authors (and fellow gunsmiths) would have us believe. Still, a properly tuned and tensioned extractor should be part of any reliability trouble shooting. I CONSIDER A LOOSE EJECTOR COMBINED WITH AN OUT OF TENSION EXTRACTOR TO BE THE PRIMARY CAUSE OF SMOKE STACK MALFUNCTIONS.

A second area of concern is the ejection port. When Colt introduced the Commander Model they lowered the ejection port for increased ejection reliability. This was probably necessitated by the slightly shorter (about 1/10") slide travel and slightly heavier recoil spring (18# rather than the 16# for a 1911). The roll over port, or teardrop, was introduced as a boon to reloaders, causing the slide to strike more towards the case head on the ejected brass, hence less likely to make a ding in the side of the case. Most people, including many gunsmiths performing this modification, do not realize that this is primarily a reliability modification. With an pistol not having a roll over port, the slide strikes the ejected case about one half way up the side of the case as the case is being ejected and the slide begins to move forward. Since the head (or base) of the case is solid and the case walls taper to become thinnest at the mouth, the center of gravity is only 1/4 to 1/3 the way up the side of the case. An unmodified slide is striking the case ABOVE the center of gravity, greatly increasing the possibility of the case being thrown back into the ejection port area--the smoke stack. I believe a roll over port is more important on a self defense pistol than on a competition pistol and recommend it to all my clients. I BELIEVE THAT A SLIDE WITHOUT A LOWERED EJECTION PORT AND ROLL OVER PORT IS A SECONDARY CAUSE OF SMOKE STACK MALFUNCTIONS.

Thirdly, heavier than standard recoil springs, shock buffs and other "recoil reducers" may, under some circumstances, produce an ejection malfunction similar, but not identical, to the smoke stack. This is most common in the Government model with the standard, short ejector. By slowing or stopping the full rearward movement of slide, the full impetus of the rearward movement does not serve to eject the shell. This form of malfunction is most frequently found when very light loads are used in a standard pistol, such as when an IPSC or self defense pistol is used for "steel matches" using very lightly loaded ammunition. The answer here is to either use a heavier load or to go to a lighter recoil spring. Shock buffs (or frame savers) are a good idea for practice sessions and matches (I carry the same pistols I compete with). Examine them carefully when you clean your pistol and replace them when they show signs of wear. I DO NOT RECOMMEND USING A SHOCK BUFF WHEN CARRYING A PISTOL FOR SELF DEFENSE. I put the shock buff in prior to the match or practice session and remove it when I get home and clean the pistol.

In summary, the old adage about smoke stack malfunctions being caused by "limp wristing" is probably a myth. It might, however, cause a marginal pistol to be more likely to smoke stack. The most probable cause of smoke stacks is a loose ejector combined with a weak extractor. Both of these parts can be inspected by the shooter when he cleans his pistol. An un-lowered ejection port on Government models and lack of a roll over port on all models, increases the possibility of a smoke stack malfunction, but is probably not a direct cause. Still, this piece of reliability tuning should be performed in all self defense pistols. Lastly, a heavier than normal recoil spring combined with very light target loads can cause an ejection malfunction similar to the smoke stack. This effect can be aggravated by the use of shock buffs or some other recoil reducers with heavier springs and lighter loads. In the final analysis, years of perpetuating the myth of the limp wrist has kept us from attempting to define the mechanical problem that is truly behind the smoke stack malfunction. Further, it has caused some portion of our population to believe the .45 auto is "unreliable". It is time to put this myth aside and begin to fully explore what the real, the mechanical, problem is. The 1911 pistol has been brought to a state of high accuracy, reliability and dependability through the studies and actions of a number of shooters and gunsmiths over many years of work and experimentation. This article is another step along the road. Good shooting.

This monograph may be reproduced only for non-commercial use without other permission of the author. Reproduction for commercial use only by written permission.

Copyright © 1998 by Les Bengtson