Gunsmithing: Do It Yourself M1911A1 Inspection and Function Test (Part 1)

Gunsmithing: Do Your Own Inspection and Function Testing on the M1911A1 (Part I)

By Steve Sieberts


Our function and inspection check test case for this month is a good, used Series 70 Colt 1911A1 pistol in reasonably good shape.

The John Browning-designed 1911A1 handgun is, quite rightly, one of the most prolific and popular handguns ever produced. But as they say on those ubiquitous GEICO insurance commercials, “everybody knows that.”

Its origins as a military sidearm and its decades of success in IPSC, Bullseye, Bowling Pin and IDPA matches—as well as it being a great defensive sidearm that is just plain fun to shoot—virtually guarantees that it will continue to be popular for many generations. As further testament to that popularity, just look at the huge cottage industry that has sprung up providing a myriad of aftermarket parts and accessories for it.

With so many variations and manufacturers of it in circulation, obtaining either a new one or one on the used market is very easy. But because there are so many available, it makes sense that some are in better condition than others. This article will show you how to perform a function/inspection check of any M1911A1-style pistol. I’ll also show some easy fixes to some of the issues you will run into, and I’ll also show when to put the pistol down and move on to another one if the defects are insurmountable. Some repairs may only need a simple stroke or two with the file, some may need a milling machine, and the worst cases will require a complete overhaul including major parts replacement.

I won’t go into the merits of the many 1911-style clones out there, and whether or not they are suitable to rebuilding. I’ll simply start with the assumption that you have found what you believe is a good, used, Series 70 Colt 1911A1 pistol in what appears to be reasonably good shape; one which has little wear of the bluing, no visible rust, and the owner’s grandmother only shot it on at the monthly Sunday IPSC match.

Before starting any checking or testing, I look to see if the pistol has had previous “gunsmithing” performed on it. If I don’t know the history of the gun, the work may be suspect and I’ll give any pistol with previous work by unknown gunsmiths a closer check. Not to say that there aren’t really exceptional unknown gunsmiths out there, it’s just that because the gun is so popular, it lends itself to modifications by virtually anyone…qualified or not.


Check for previous pistolsmithing by looking for large gaps in the fit of any aftermarket beavertail grip safety unless it is of the drop-in variety.


After I’ve checked the pistol to make sure it’s unloaded, the first thing I do is to perform a series of safety and function checks. This will tell me if there is anything internally wrong that needs to be addressed, and also the severity of those defects.

The first check I do is of the various safety systems of the pistol. Make sure the hammer is cocked and try to engage the thumb safety, located on the left side of the gun. It should be easy to slide up and down into the engaged and disengaged position with audible clicks. It should also be somewhat stiff, but not excessively.

Push the thumb safety up into the engaged position and leave it there, then try to pull the trigger. I look to make sure the hammer does not move. Sometimes you can see this movement and sometimes you cannot. If it does, you have a very short safety and it is definitely something that you want to fix right away. There is a way to correct this temporarily without replacing the safety, I’ll show how later in Part II of this series.


Push the thumb safety up into the engaged position in order to start the thumb safety check.


After engaging the thumb safety and squeezing the trigger, drop the thumb safety and try to ease the hammer back. The hammer should not move nor should the sear click throughout this test.

Even if it doesn’t move, there still may be a short safety condition. With the safety still disengaged, try to ease the hammer back and listen for an audible click. If I hear it that means that the thumb safety is too short and is allowing the sear to move out of the hammer notches. The click is the sear snapping back into its proper position.

The thumb safety is supposed to absolutely block all movement of the sear, and anything less is unsafe. There are three ways to fix this situation: you can replace the thumb safety, weld it up where it engages the sear, or peen the stud portion of the thumb safety to build it back up.

This last method is really only a temporary fix. So, to repeat, the drill for this check is to rack the slide one time. Don’t retract the slide and let it slingshot forward on an empty chamber, it’s pretty hard on the pistol. Rack the slide, push up the thumb safety, and then try to press the trigger. If the thumb safety is extremely short, the hammer will fall. If the thumb safety is just slightly short, the hammer will move slightly forward.

I then DIS-engage the thumb safety and try to ease the hammer back with my thumb. If you hear a click, the thumb safety is slightly short, but is still an unsafe condition and must be fixed. What is happening is the thumb safety is allowing the sear to slightly rotate out of the hammer notches and when you pull back the hammer, the sear is snapping back into the hammer notch. The thumb safety should always completely block any movement of the sear.

Sometimes, the sound of the sear snapping back under the hammer hooks will be so faint that I will have to put the pistol up near my ear to listen for it. Be aware that if you do this test at a gunstore or gunshow, you will get some funny looks when you put the pistol up near your ear. I know I always do, but I get even more confused looks when I hand the pistol back and tell them the pistol is unsafe and they need to fix the thumb safety because it’s too short. I was at a large gunshow one time and actually had a sales person look me in the eye when I performed this check. I pulled the hammer back and let him hear the snap of the sear going back into the hammer hooks and told him the thumb safety was too short, he told me the pistol was designed to work that way! I just gave it back to him and walked away. The sad part was he was being serious.


Test the grip safety by inverting the pistol with the hammer cocked and try to press the trigger. This tests not only the grip safety, but also the right leaf of the sear spring where it bears on the grip safety for proper tension.


            The next safety to check is the grip safety. The way to check this is to rack the slide, cocking the hammer, and point the pistol toward the ground without depressing the grip safety. Try to pull the trigger. Just like with the thumb safety, look at the hammer, which should not fall. With this check, we are not only checking the length of the grip safety to make sure it’s blocking the back of the trigger stirrup, but by pointing it to the ground, I’m checking to make sure the right leaf of the sear spring has enough tension to keep the grip safety engaged, that it is not dis-engaging by it’s own weight.

I also want to make sure that if I grip the pistol in a normal firing grip, pull the trigger, rack the slide once, and release the grip safety, it should “pop” out or dis-engage when I release the trigger. In other words, the trigger should release forward, and the grip safety should pop out rearward at the same time. The grip safety test is performed assuming that the grip safety has not been “pinned” or otherwise deactivated. This is a common practice on competition pistols, but should never be performed on a gun used for self-defense. I always do all of these tests by racking the slide, rather than just cocking the pistol, as this gets the internal parts in orientation, as they would be as the gun is cycling when being fired, as opposed to just cocking the hammer back with the thumb.


Start the disconnector check by pushing on the front of the slide with the palm of the hand until the barrel drops out of battery.


Another safety of the 1911A1 design is the disconnector. While not an active safety that is engaged by the operator, it nonetheless performs an extremely critical function. This is an internal safety that ensures that the pistol will not fire if the gun is “out of battery.” In other words, this prevents the pistol from firing if the barrel and slide are not completely locked together and in the forward position.

The way this is checked is by starting with the hammer back, then, with the palm of the hand, push the locked slide and barrel back at the same time until the back of the barrel drops down out of battery. Pull the trigger, the hammer should not fall, don’t release the trigger, then let the slide and barrel return to battery, making sure the hammer doesn’t follow the slide down. Keep the trigger pressed, and rack the slide one more time. Don’t slingshot the slide. Release the trigger and the disconnector should reset, now press the trigger and the hammer should fall. If the hammer does fall, the disconnector could be too short, or the sear spring might be too short or weak.

These three checks will give me an idea of the overall safety of the pistol. They should only take about a minute, but can really tell a lot about the pistol. Once I’ve looked at the pistol overall, and have performed these three quick function checks, I then look at the outside of the pistol land look at the overall condition.


As I mentioned earlier, I always look for previous gunsmithing work. One area where poor work will be glaringly obvious is if the pistol has had an aftermarket grip safety installed. Since this is one of the most common gunsmithing jobs, it’s the first place I look. To start, I check if the grip safety is one of the drop-in models or one that has to be fitted. If it’s a drop-in model, I ignore the gap between the grip frame and the grip safety on the rear of the tang because the gap is normally pretty large by design. If it’s a fitted model such as the Ed Brown, Smith and Alexander, or others, look for the gap. If a professional fit the grip safety, the gap between the frame and the grip safety will be just a hairline all the way around where the frame and the grip safety meet. If it’s anything less, then the pistol has probably been worked on by someone less experienced, and I will inspect this pistol more closely once I get it apart.

The next spot to look is another commonly modified area on the pistol, and that is the sights, both front and rear.


There are basically three ways to install a set of sights on the pistol. The way sights used to be installed, especially the front sight, was by using a torch and silver solder. This is an effective way to install sights, but can lead to problems. I don’t like to use this method simply because I don’t like to put a torch on a gun unless I absolutely have to. Second, silver solder was popular on the National Match hardball guns I shot on the Army Shooting team, and on occasion, the front sight would come off the gun due to the forces of repeated recoil from heavy hardball rounds. The heat of the torch applied to the small tenon of the front sight lead to weakness over time, especially if the slide wasn’t heated up enough.

The second way to install a set of sights is by using the swage and epoxy method. With the excellent epoxies available today, this is an excellent method if done right, and keeps the torch off the gun. I will be outlining this method in future columns.

The third way to install a set of sights is by using a milling machine and is beyond the scope of this column simply because few home hobbyists have access to a quality Bridgeport mill. I have installed hundreds of sights this way and it is my preferred method. Since installing sights on the pistol is so popular, look and see what installation method was used, and look at the craftsmanship of the job. If the front sight leans to the side, or if there are large gaps between the base of the sight and the slide, then the installation was sloppy.


Always check your dummy cartridges for overall length with a good set of calipers. Minimum OAL should be no less than 1.190. This round comes in at 1.168. It still works, but if it was causing the pistol to malfunction, I would use a better round for testing.


Another great check is to see if the pistol can cycle dummy hardball cartridges successfully. You probably won’t be able to perform this test at a gunshow or at your local retail gunstore, but if you can get the gun to your home workbench, try it out. I keep dummy cartridges on hand for any firearm I’m working on just as a quality control check.

For this test, load a magazine with non-firing dummy cartridges into a magazine that you know has functioned reliably in the past. I use dummy hardball rounds for this test. Make sure that your overall cartridge length is not too short. Repeated function testing with dummy rounds will eventually push the bullet deeper into the case, reducing the overall cartridge length and giving false results. The minimum and maximum overall cartridge case length that SAAMI (Sporting Arms and Ammunition Manufacturers Institute) specifies in their specifications for 45 ACP round nose ammunition is 1.190 and 1.275 respectively. I always check my dummy rounds to SAAMI specs fairly regularly with a good quality caliper.

Load the magazine and cycle the rounds vigorously, looking for smooth feeding, chambering, extracting, ejection and cocking of the hammer. I perform this check with the trigger pressed since this is how the pistol will cycle when firing. Cycling the pistol without holding the trigger to the rear while performing this check may cause the trigger to bounce forward and then backward, tripping the disconnector and sear, causing the hammer to fall, and giving a false indication that the gun has a disconnector issue or some other internal problem.       With the trigger pulled, the disconnector and trigger are out of contact with the front legs of the sear. We should have already established that the sear and disconnector is in good shape from the function test we performed earlier, so I should have already discovered a bad disconnector previously. While performing the cycling test, look for the rounds coming out of the ejection port in a fairly consistent direction. Ideally, they should land in a four-foot circle over your right shoulder and behind you if you are standing up. It won’t be exactly like simulating actual firing, but the ejection pattern should be a close approximation to what happens when actually firing. If the pattern is random, the pistol could have a loose extractor or ejector, which is something that is easily fixed. I also want to make sure that the magazine seats fully without excessive pressure, and that the magazine falls away from the gun when the magazine button is pressed.

It really shouldn’t make a difference, but I usually start this test with the slide locked to the rear, to make sure the slide release fully engages the notch in the slide. I then insert the magazine, making sure the left side of the bullet nose does not bump the slide release. Grip the pistol with the firing hand, press the trigger and depress the slide release, letting the slide chamber the cartridge. Then I hand cycle the cartridges one by one until the magazine is empty. At this point the slide should lock to the rear again.

By now, I have inspected the pistol for obvious overall defects and looked for work done by previous pistolsmiths. I have inspected the pistol’s safety systems, and function tested it with dummy cartridges to expose possible internal problems. I have a good frame of reference as far as what type of work the pistol needs and what parts I may need to replace to make it safe and functional. If the gun passes all of these tests, I can be pretty confident the pistol is safe and functional and is probably a good candidate to purchase.

If the pistol doesn’t pass these tests, it still may be a good candidate to buy, but at least now I know what I need to repair or replace. I still need to disassemble the pistol and perform a more detailed inspection to see what work may have been performed and what internal parts may be needed.

The next phase is to look for cracks and other defects in the major components such as the slide, frame and barrel, and to detail disassemble and inspect each part thoroughly. I’ll cover all of that next month in Part II.

About the gunsmith: Steve Sieberts has been in the firearms industry for more than twenty years, and has certificates from five gunsmithing schools, eight factory armorer’s courses, and—perhaps most importantly—was the Chief Gunsmith for more than a decade at a classified Department of Defense facility involved in R&D, manufacturing and testing and evaluations of small arms for the military. A former member of the Army Marksmanship Unit, he has earned the Distinguished Pistol Shot Badge, President’s Hundred Tab, and is a member of the NRA 2600 Club. He shot IPSC for many years and currently competes in IDPA matches.


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