In observing the discussion of the reliability, longevity, and overall performance of 1911s, I find that there is a huge disparity in what folks consider to be "a lot of rounds" or a reasonable test cycle. It is not uncommon to hear that someone's gun has "never given them problems" or "runs great," only to find out that they have only shot 100 rounds out of it over the span of two range sessions. Since this site is aimed at professionals and serious students who could benefit from quality information and discussion, I thought it would be worthwhile to put some hard numbers out for discussion. Keep in mind that the component and build quality of the gun, as well as the type of ammunition and magazines, can drastically affect performance. The numbers below are guidelines, determined from my own experience and observation. They are also related to full sized, steel frame 1911s firing full power .45 ammunition. Hand built competition 1911s firing reduced power handloads or those fitted with compensators tend to exhibit different service cycles, and many of them tend to last quite a bit longer.
First, let's consider what should be a statistically significant round count interval. Firing 50 or 100 rounds through the gun is not worth terribly much as far as diagnosing its overall performance, unless you are looking at a very specific area. If you are doing very focused performance testing, 50-100 rounds can be worthwhile if you are looking for an expected outcome. For example, if you need to see if the gun is ejecting consistently, 50-100 rounds will give you some decent information. However, to get a bigger picture of overall performance, 300-500 rounds is the minimum you should accept before making any judgments regarding overall performance. If you are watching the gun closely, it is possible to get a pretty good read on the weapon's performance within 300 rounds. If I built the gun, I can usually predict how it will run after a 300 round test session because I am looking closely at certain criteria.
To stretch out the discussion point here, I personally consider 1,000 rounds the standard interval that I examine for reliability and function. If a particular gun/ammo/mag combination will run for 1000 rounds without incident, that is meaningful to me. One malfunction in 1,000 rounds is the maximum that I will tolerate, and even then I am looking very hard for the root cause of the problem. Since the original 1911 underwent a 6,000 round trial without malfunction, it should be reasonable to expect a properly set up weapon to duplicate the same performance with quality magazines and ammunition.
The mainspring and sear spring are under a very light load, and quality units tend to last longer than the round count milestones discussed below. Neither spring typically requires replacement in normal service, which includes keeping the hammer cocked at all times. The longevity of the fire control components – hammer, sear, and disconnector – will vary based on the quality of the parts. High quality machined parts that are fit and set up properly in the gun will generally exceed the service cycle milestones listed below with no noticeable change in feel or performance.
Round Counts – Meaningful Milestones:
The 1911 platform will last far, far longer than the 6,000 rounds from original military trials. However, that long road is not without meaningful milestones that should be respectfully and diligently observed by the dedicated user. These intervals that follow apply to my experience with 5" 1911s shooting .45 ACP, and each gun is going to be very different.
500-1,000 rounds – If you are running a synthetic buffer in your gun, this is the interval at which you need to replace it. If you wait too long, the buffer will come apart inside the gun and tie it up. Five hundred rounds is a reasonable interval at which to perform basic cleaning, lube, and maintenance on your 1911.
3,000 rounds – Every 3,000 rounds should see the replacement of the firing pin spring and the recoil spring. Timely spring replacement prolongs the service cycle of the weapon.
3,000-10,000 rounds – This seems to be the lifespan range of the average slide stop detent plunger and the accompanying plunger spring. Why is this significant? The detent plungers, if made to the original ordnance specifications, are only surface hardened about .002" to .005". More often, modern pin sets are not made to such specification, and the tips of the plungers flatten out with age. A flat headed plunger does not exert the appropriate tension on the slide stop, and in conjunction with a weakened plunger spring, can lead to premature or false slide lock malfunctions. Make a habit of periodically examining your slide stop plunger when you perform maintenance on the gun.
This same round count interval is also when many factory plunger tubes tend to loosen from the frame. This is a show stopper and the gun must be pulled from service immediately. It is possible for the safety detent plunger to ride out over the safety while it is in the "safe" position, making it physically impossible to lower the safety and fire the gun. Standard ordnance pattern grips will support and pin the plunger tube to the frame, which conversely is why slim grips are a bad idea. Take a look at your grip panels and see if they help keep the plunger tube in place.
5,000 rounds – This is what I find to be the low end of the average lifespan range of the modern internal extractor. Yes, plenty last much, much longer, but plenty also last only a fraction of this round count. Once an extractor starts to log this many rounds, I will typically replace it at the first hint of failure (ie. erratic ejection). Some important caveats are necessary in explaining this very harsh and short service interval. Once the extractor is properly set up - and this will require a skilled hand for fitting as well as some test firing - the extractor should be good to go for its whole service cycle. Once it starts to let go, it is on the downhill slide and more problems will continue to surface. The first time you get a profound extractor related malfunction, don't shrug it off, you're going to get more. The extractors often will continue working with some retensioning, but that can sometimes just be a temporary fix. The key issue here is that extractor failure is typically only recognized (if at all) by the shooter as a stovepipe or double feed malfunction, where that really is the most extreme situation. If you start seeing rounds ejecting forward, left, and straight at the shooter's head, THAT is the beginning of extractor failure. This milder type of failure is often dismissed, which is why extractors may often seem to last longer.
20,000 rounds – About the time to start giving the gun a comprehensive overhaul to look for worn components. Cracked firing pin stops, cracked or bent barrel bushings, and peened barrel lugs (both lower and radial) may start showing up. If the gun started with a relatively modest or loose slide/frame fit, they may be pretty loose by now. If the gun still works fine, it's not a big deal, but retightening the fit between the slide and frame can give the gun a whole new feel.
20,000 – 30,000 rounds – About time to start looking at the bore if you've been shooting jacketed ammunition the whole time. However, as long as there is some rifling left in the last 1" or so of the tube, a good barrel will often continue shooting just fine. Thanks to John Miller from AMU for that nugget of wisdom. I have a gun that is missing a large percentage of rifling in the first third of the barrel, yet is still a tack driver. Barrels may be reaching the end of their service cycle around this point due to wear in the overall fit. The longevity of the barrel fit will have much to do with how it originally fit in the gun. The better the fit, the longer the barrel will tend to last.
50,000 – 70,000 rounds – A lot of guns start to really show their age once you get past this mileage point. Slides and frames can start to develop cracks, and excessive wear in various small components starts to add up as well. Broken or loose ejectors, cracked thumb safeties, loose ambi safety shafts, broken hammer struts, broken slide stop lobes, loose plunger tubes, and loose sights are all common ailments of the small parts. It's time for at least another rebuild, this time you may need to look at replacing the slide and barrel. A lot of life can be squeezed out of the frame as long as the pin holes remain round and the barrel bed is not too worn from barrel lug impact. Ultimately, it may be easier to retire the gun at this point, as you may end up chasing a lot of different breakages.