Slide not locking back on last shot

[Conservidave]

as the title says the slide on my RIA 9mm 1911 hasn't been locking back on the last shot. I thought that maybe my ammo was the culprit and it may be, however it's the same load that i've shot probably a thousand times but the last trip to the range this began happening. I'm thinking it's gotta be ammo or the magazine.... What say the THR experts?

Dave,

 

[judgedelta]

No expert, but change one thing at a time and see if the problem goes away... Magazine follower engages the slide stop. Does it lock when you pull it back by hand?

 

[Jim K]

First, have you changed anything? It is easy to check the engagement of the magazine follower with the slide stop - just remove the slide and look down into the frame to watch the action.

Jim

 

[Conservidave]

It will lock back by hand no problem. I'll check the engagement as soon as i get a chance. Hopefully it's no worse than replacing a magazine.

Thanks Gents!

Dave,

 

[wmueller139]

Could be way off, any chance you changed your grip on the pistol? The way I hold my 1911 my weak thumb hits the slide stop lever and due to this it will not engage after the last round.

 

[Prince Yamato]

The slide not locking back can only be one of two things:

1) your mags followers are not engaging the slide lock

2) the slide lock is not engaging the slide.

One of my Glocks is particularly sensitive to this. It's most likely my grip, as I replaced the slide lock. Check your mags, then check your grip.

 

[JDR]

This is a problem for me when I shoot a lot of different pistols with a thumbs-forward grip. In all probability, one of your thumbs is bumping the slide lock lever downward on that last round. I have to remember to keep my thumbs away from the frame of the gun. My HK P30 and my Sig M11-A1 will both often fail to lock back after the last round, I never have this problem when I shoot my Glocks. This is an issue when I'm practicing slide-lock reloads, but this is not a problem when I'm practicing tactical reloads.

 

[ThePenguinKnight]

My RIA had a faulty slide lock lever, which did not protrude far enough into the mag well to engage the followers. That'd be the first thing I'd check.

I have a hard time accidentally touching the 1911's slide release. Hard for me to imagine that to be the problem with any normal grip on the pistol, but I guess that's worth watching for also.

 

[imashooter]

Using the same empty magazine inserted to the pistol, it'll lock back when manually pulling the slide back?

Light Loads: try stouter or a different brand

Recoil spring too heavy

Slide stop: Many folks experiencing similar problems have good luck with replacing assorted manufacturers stops with the Wilson Combat .38 super / 9mm slide stop.

Magazine: If the follower tilts rearward during operation, this can prevent lockback after the last round yet allow lockback if the slide is manually moved to the rear locked position.

Thumb resting on stop during firing.

Hopefully it came with the correct slide stop and not the .45 stop which is a tad shorter on reach to the follower.

 

[imashooter]

Didn't read it all but it's likely a good thread. https://forums.1911forum.com/showthread.php?t=500042

 

[Bullseye57]

I'll throw this one into the mix, do you have a "shock buffer" rubberized recoil insert pad, installed? I have seen these interfere with the slide's ability to travel fully rearward. If not, this is a timing issue that in addition to the other suggestions can also be caused by a weakened magazine follower spring.

R,
Bullseye

 

[Taurus 617 CCW]

This may be a stupid question but have you tried lubing it before checking for slide stop function?

 

[Conservidave]

can also be caused by a weakened magazine follower spring

First of all thanks for all the helpful suggestions. I have checked the function of the the stop and follower and everything seems to be ok when tested by hand. My grip hasn't changed dramatically since my last range trip and my ammo is coming from a box of 300 i loaded a month ago. I only started having the problem at my last range trip so I'm leaning to the factory mag/spring starting to weaken enough to lose that critical timing.

Are the McCormic Magazines any good? (they're not cheap)

Dave,

 

[Missouri Farmer]

Is it possible that your thumb is pushing down on the slide lock while you are shooting?

 

[Taurus 617 CCW]

1.) Try lubing the gun and test it out.

2.) Do a deep cleaning and lube.

3.) Change magazines and test it out.

 

[sawdeanz]

I have this problem when my wrist is too limp, concentrate on having an extra firm grip and see if it still has the problem.

 

[[email protected]]

I had a similar problem out of my para Gi several years back. Turned out to be an out of spec slide stop lever. The lever would be pushed out of the frame enough for it not to catch on the slide.

 

[Normandy]

I had the opposite problem with my Citadel (by Rock Island) 9mm 1911. The slide would lock back when there was still ammo in the magazine. I swapped out the slide stop, and the problem went away.

I know that's not very helpful for your problem, but just thought I'd mention it.

 

[Walt Sherrill]

so I'm leaning to the factory mag/spring starting to weaken enough to lose that critical timing.

I haven't spent a lot of time with 1911s, but...

I don't think "timing" is a critical factor for an empty mag (but there are things I don't understand, and I may be wrong.) Timing problems from weak springs tend to be a factor when the spring isn't lifting the next round quickly enough to be caught by the slide as it moves forward. That IS crtical, and noticed when someone installs a heavier recoil spring.

Do you have more than one mag? (If you don't, you really SHOULD have more than one!) If you don't, try to borrow one. A different mag would tell you whether its a mag issue, or not. If you have two mags, one that works and one that doesn't, disassembling the two mags -- the good and the bad (keeping the parts separate) -- would let you see if anything is noticeably different. Be warned: very new mag springs are always much longer than ones that have been used; springs take a set quickly, and will shorten, but still work properly.

There's a small chance something has happened to the slide stop lever, but if a known good mag isn't affected, it's not the slide stop.

It might be that the problem mag spring isn't strong enough to push the follower up flatly or properly when the rounds are all gone -- but the fact that the mag worked properly for the other rounds suggests the spring MIGHT be OK.. (Having the mag spring in wrong could give you the same problem with the last round, but that would generally cause feeding problems, too.)

Note: racking the slide by hand isn't going to give the same "motion" as letting the slide do it after the last round is fired.

 

[L-2]

Since you're shooting your own reloads, go back to post 9 and try a well-known/proven factory ammunition. All the suggestions are sound and any one of them, or even a combination, could be the culprit. (I know, as I've experienced them all with my .45 caliber 1911 guns; I don't have a 9mm version).

Back to the ammo. This is just to eliminate as many variables as possible to define this elusive problem.

 

[Zach S]

Just one factory magazine? Uh, dude, you gotta get more mags...
I use nine round Metalforms. They have two different styles. One is a .38 super tube with a removable spacer in the rear, and a removable baseplate. The other has the spacer formed in the front, and a welded baseplate. They're commonly called "Springfield style" or some variation of that. I have five of one style, six of another. I haven't tried any others because these work.

It could be a magazine spring getting weak as well.

 

[Bula]

I developed that issue on a Browning HP then a Glock 26. Hand load was not a powder puff load (125g cast at 1075-1100). Realized it was my off hand thumb riding the side of the slide stop. Not forcing it down, just resting on the side. Adjusted my grip and issue resolved. The fact that the slide locks on an empty mag manually manipulated, has me leaning towards some shooter contact.

 

[nettlle]

Have you ever cleaned the inside of your mag? My mags got gummed up and the follower would hang intermittently.

 

[Drail]

How heavy is your recoil spring? A magazine spring that has weakened will start having last round feed malfunctions in addition to not having enough strength to lift the slide stop up fully. Look carefully at the locking notch in the slide - is it peened (corners chewed up)? Try removing the slide from the frame and reinsert the slide stop. Watch the interaction between the slide stop and the magazine follower as you insert an empty magazine. Is the follower engaging and lifting the slide stop all the way when the magazine is fully inserted? New springs would be a good idea only because the factory originals weren't very high quality. Wolff makes an extra power magazine spring that improves feeding greatly and helps get the slide stop up. I wouldn't replace any parts until you have observed the operation with new full power springs. Don't fall for the advice of using a heavier recoil spring - they usually cause more problems than they solve.