Gunsmithing: Do It Yourself M1911A1 Inspection and Function Test (Part 2)

Gunsmithing: Do Your Own Inspection and Function Testing on the M1911A1 (Part 2)

To start with Part 1 of this series, click HERE

By Steve Sieberts

My previous post covered the initial inspection and function testing of a new or used 1911A1 auto pistol. This time, we’ll cover basic and detailed disassembly and inspection.

Some of the disassembly steps outlined in this entry may or may not exactly match your pistol, depending on things like what type of recoil spring it has, etc. For our purposes here, I’m going to assume that you have a basic 5-inch Government Model in .45 ACP.

There is a couple of ways to field strip this pistol, and as always, having the right tool for the job is critical. A nylon or steel bushing wrench is essential for a pistol that has a fitted Match barrel bushing, but the pistol can be disassembled without one if you have a pistol with a loose or factory barrel bushing. I have several bushing wrenches that suit a particular barrel/bushing configuration, and most pistolsmiths will have more than one if they work on the pistol for any length of time.

Starting with an unloaded pistol, and assuming that I have a standard-issue model without a fitted bushing, retract the slide rearward so that the slide release lines up with the disassembly notch on the slide.


Retract the slide to the slide stop notch and push out the slide stop from the right side of the gun.

Push out the slide release from the left to the right. Once it pops up, remove the slide release, keeping control of the pistol. Let the slide go forward with the right hand, while controlling the recoil spring as the slide comes off the frame.


Ease the slide off the frame while trapping the recoil spring with the left hand. Remember, the spring is under great pressure.


Remove the recoil spring assembly

Be careful: the spring is under pressure. One of the hazards of working with firearms is that there are many parts under spring pressure, and if that pressure is not controlled, springs will go flying! At best, you will lose a spring and have to get on your hands and knees and do the “gunsmith’s crawl” in order to find it or buy another one. At worst, however, you can damage your eyes, or the eyes of someone else.

Always be careful when working around firearms for this reason. Eye protection is mandatory at all times at every gunsmithing school in the country. I’ve had metal embedded in my eyeball on two occasions, and I’ll just say that the doctor will remove it with a hypodermic needle. Not fun!

Anyway, once I have the slide off the pistol and have removed the recoil spring and recoil spring guide, rotate the bushing clockwise and then remove the recoil spring plug. Then rotate the bushing counter-clockwise and remove the barrel and bushing from the slide.

If you are working on a pistol with a fitted Match barrel and bushing, and are doing repeated assembly and disassembly, always rotate the bushing around the smaller diameter area of the barrel, this will reduce the wear and tear on the bearing surface of the barrel and bushing. In a Match barrel, the last ½-inch of the barrel is .005 larger than the rest of the barrel. This is where the barrel and bushing are tightly fitted for greatest accuracy. I always slide the barrel forward so the muzzle sticks out the end of the bushing, which enables the bushing to be rotated around this smaller area.

So now we have the pistol partially disassembled, or “field stripped.” At this point, I can perform a detailed inspection of the external parts of the pistol, prior to detailed disassembly.

Looking at the barrel, there are many areas that need inspection, and there are two important questions to consider when inspecting a new or used pistol. First, do the parts have cracks in critical areas? And second, has a previous owner worked the pistol?

One of the first areas of the barrel to look at if the pistol has seen any use is cracks. It doesn’t matter if the pistol has only been shot a few rounds; I have seen barrels crack after only ten to fifteen rounds.

I usually inspect a part from front to back and side to side and top to bottom. Look at the muzzle and check for nicks and damage, and look to see if the pistol has been the recipient of a previous job of re-crowning. Especially look for nicks and damage that extends into the rifling. For example, I have re-crowned this Match barrel on a lathe with an 11-degree target crown. The other barrel is factory original.


Side by side comparison: factory barrel throat on the left, Match barrel professionally throated to feed wadcutter ammunition on the right. This is one of the most botched jobs performed on the 1911A1 pistol. It can also make it unsafe if the throating extends too far into the chamber, leaving the back of the cartridge case unsupported. It can cause the case to blow out.

Going back to the top locking lugs, look for rounded edges on the leading edge of the top locking lugs. I have seen where the front corners on these top locking lugs were completely filed away. Very unsafe! These lugs lock into recesses cut into the corresponding locking lugs in the slide. Also inspect the corners of the barrel hood and look for cracks in the corners of the hood.

Another good spot to look for previous repair work is by opening up the barrel ramp. This is probably one of the most botched jobs in all of pistolsmithing. Done correctly, it can ensure that the pistol feeds reliably with almost all types of ammunition.

Remember, when the original pistol was developed, the 230 grain round nosed hardball projectile was standard. Since then, there are myriad types of bullet nose configurations. The problem is that many times, people do not have the experience to properly diagnose malfunctions, or might jump to conclusions as to a pistol’s failure to feed or chamber a round, and immediately think that the pistol needs to be throated, where it might be a case of a bad magazine or a burr in the firing pin hole, or the breech face is too tight, or the extractor is not fitted properly, or the bullet is seated out too far, or a hundred other reasons for the pistol malfunctioning.

I have seen some truly horrendous jobs, and many times, the barrel cannot be salvaged. Any pistol that has been modified to the point of being unsafe should be fixed immediately.

This is where a pistolsmith earns their money. A good one will know what is and what is not a safe modification, and when to replace the part or parts. One thing to look for is whether or not there is a change of angles. If the angle on the barrel throat is changed, it’s usually a case where the barrel is modified in an unsafe manner and is beyond being salvaged and should be replaced.


My Go/NoGo Headspace gauge. Measuring against the barrel hood. This is a quick check for headspace. The barrel hood is not a reliable or an actual reference point of measurement. But it serves as a quick check.

Check the headspace with a headspace gauge. I have one that is a no-go gauge that has a step surface ground into it to make a go/no-go gauge.

The bottom locking lugs should also get special scrutiny. These are where the barrel sits on the slide stop when the pistol is in full battery. It is one of the three areas of barrel fit that directly affects the accuracy of the pistol, the other two being the top locking lugs and the barrel bushing/ bushing to slide fit.

Look at the rear of these bottom lugs. Look at the slot for the barrel link. That slot is a prime area for cracking. Anytime a part is machined with a sharp corner, it creates what’s called a “stress riser” and is a likely spot to look for anytime pressure or force from repeated impacts takes place.

When the pistol is fired and recoils, the barrel is pulled down out of battery by the barrel link, and comes to a stop on the frame bed.

Another area to look for on the bottom lugs is if the barrel lugs are crashing into the slide stop pin. This area needs to be cleaned up so that is doesn’t happen. I’ll cover how to do this in future columns on barrel fitting. The link has to clear the front area of the bottom locking lugs for best functioning.

One check I always do is to take the frame, barrel and slide stop and insert the slide stop through the barrel link without the slide. Set the barrel down onto the frame bed as if the barrel was in the unlocked position. There should be a gap between the barrel mouth and the feed ramp on the frame of about 1/16th of an inch. THE TWO ANGLED SURFACES SHOULD NOT MEET! Many people with try to grind away the feed ramp to take away this gap in the mistaken notion that it is causing feeding malfunctions. In reality, if that step is taken away, it will CAUSE malfunctions.

Another check is to look down the inside of the barrel. I realize that most home gunsmith’s don’t have a borescope, but try to look down the barrel with a strong light and look for sharp rifling. .45 ammunition is pretty low pressure, in the neighborhood of 21,000 psi, where centerfire rifles go around 50-65 PSI’s. So there probably won’t have erosion from extensive shooting like you would see from a high-powered rifle, but the rifling at the tops of the lands should still be sharp.

Lastly, make sure the barrel link pun is staked in with a center punch. You don’t want this pin walking during firing.

The bushing gets a quick check to make sure that the locking tab is not damaged. Also ensure that the bushing skirt is not cracked, as can sometimes happen if the bushing has been expanded in an attempt to accurize the pistol.

That’s it for now. Next time I’ll take apart the lower half and perform a complete inspection on those parts. I will also disassemble and inspect the slide, then reassemble the pistol and perform a final function check.

In future posts, we will build a custom carry 1911 starting from a box-stock pistol. Stay tuned!

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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