Recently took my brother in law to the range. He brought along a Phillipine made 1911A1 that his brother had given him years ago. Had Pahrump, Nevada imported stamp. While the pistol shot well the slide failed to lock back after last round. It would lock back on empty magazine by manually racking slide. It had a generic after market magazine. It was completely dry of any lubricant. (He is not a "gun guy".) I took it home at his request and gave it a good cleaning and lube. I researched problem and there were many answers from magazine \ follower issues to low power ammo to weak recoil spring.

My question is this. Could it have been caused by a dry pistol (no oil at all). Haven't shot it since as I have it back to him after cleaning and oiling.

1911's like to be run wet.

Failure to lock the slide back after the last round can be due to a few different causes.

1) If the recoil spring is weak or worn for the load being used, the slide velocity will be excessive and the slide will rebound off the frame. This results in the slide passing back over the magazine follower before it can rise high enough to lift the slide stop to catch the slide. Of course, this also usually results in failure to feed loaded rounds, specially with a near empty magazine when the magazine spring pressure is at a minimum.

This rebounding off the frame also batters the frame.

2) Many shooters will install a shock buffer. This is done to reduce frame battering (often without replacing the weak spring that is causing the problem), but it also has a side effect of reducing the total slide over run distance, and can actually shorten the slide over run time, leaving less time for the magazine follower and slide stop to do their thing.

In the full size 1911, it's not that big a deal as there is ample slide over run, but in a Commander size 1911 it can be an issue, and in the Officer frame sized 1911 it is a significant issue as there is already very little slide over run and there is not enough margin to tolerate a shock buffer.

3) A weak magazine spring can be an issue as can a follower that is sticking slightly in the magazine.

4) The slide stop/release lever itself can be an issue if it is poorly fit, or inadequately lubricated. The pin has to rotate in the frame and in the link, and there can be some drag on the frame. This can slow the rise of the slide stop and prevent it from rising enough to catch the notch in the slide before it goes by.

5) All of the above can combine to create the problem.

A too heavy recoil spring, compared to the power of the ammo, can cause the slide not to lock back on the last shot. This might be a possibility since you say it will lock back on an empty magazine. Lube is good, too, especially on the rails. Some lube on the outside of the slide's firing pin channel may also help. Recently, I was at the range with a buddy who has a new Kimber sub-compact 1911. My buddy said that he liked to shoot a new pistol dry (it was quite dry), to break it in. It kept malfunctioning. I got a bottle of lube and with his permission, oiled up the Kimber. It functioned without any problems after that.

Easiest thing to check is a weak magazine spring.
Too weak and it won't kick the follower up and then the slide stop fast enough to catch the slide.

Take the magazine follower and spring right out of the mag body.

Drop a couple rounds of ammo down into the magazine.
Then put the spring and the follower back in the mag body.

All you've done is increased the spring tension in an 'empty' magazine by putting those rounds under the spring. (of course it lowers the capacity but for this experiment, we only want to know if the spring itself is weak).

Now with this restructured magazine,,load 1 or 2 live rounds into it and fire them off. See if the stronger spring tension under the follower after the last shot makes the slide stop function as it should.

If it does,,then the mag spring is the culprit.

Either change magazines,,1911 mags are pretty cheap.
Or you can simply try and stretch/pull the mag spring out a bit and see if that holds a set in that elongated position to make the assembly work as it should.
It may do that,,or may for just a while and then go back to not working if the spring has taken a set to the scrunch position of less tension.

If none of this makes any difference in performance,, it costs nothing to try and it elliminates one possible issue from the list for you.

Thanks that was my first thought at the range. I didn't take any of my 1911A1's so I couldn't try different magazines (He only had one.) It seemed the magazine he had was a bit ill fitting when pushing it in and sometimes it would not eject when pressing the releases button. Next time I take him we will try some different ones.

First thing I usually look at is the ammo. Is it hand-loads? If Factory it's usually one of the above problems. If hand-loads most probably they are low powered and not allowing the slide to move fully back on recoil.

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H Richard
SWCA1967 SWHF244

Now that it is lub/cleaned, take it to the range and fire using 230gr MJRN ammo

Often, the cheaper magazines need the follower adjusted so that the shelf that contacts the slide lock and causes the slide to lock open needs adjustment. Sometimes the tab on the slide lock itself doesn't make good contact with the follower or does not move as freely as it should. These are things to check.

Insofar as the magazines themselves go, use a dry lubricant if you're going to lubricate them. Oil should not be used in a magazine for the very same reason it should not be used in a firing pin or striker channel; oil collects grime and causes loss of proper function. Followers should be checked for binding or roughness. disassembly and polishing and adjusting follower legs can go a long way toward taking care of these problems.

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Dave Frost

I'm guessing, based on the OP's posts, it's the magazine.

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Thread Killer.

Probably the cheap magazine is at fault. I'd try a Metalform or MecGar 7 round magazine and see if that solves the problem.