Malfunction question on Semi auto?

E

Eric Larsen

New member
I have had guns in the past that do this and need to know why?

After firing a round the slide goes back and gets stopped just before taking the next round out of the magazine. If you rack the slide it takes the round right out and chambers it. It isnt ammo
specific, just happens when it feels like it.

Condition of the guns that it happens to....polished feed ramp, throated chamber, new mags w/ good springs, standard recoil spring which I assume is in good shape. Newer guns less than
1 K rnds through them.

Guns are cleaned including mating surfaces on frame and slide.
No spring binding that I am aware of. Guns have had full length
guide rods and sometimes new factory recoil springs. Well lubed
with CLP mostly, sometimes grease on slide parts..just for good measure..very little when I use it.

Is it an ammo problem? Recoil spring? Both? HELP!

Any help would really be appreciated! shoot well
 
What type of firearm and magazine are you using when you experience this?

I am NOT a pistolsmith, but it sounds like it could be magazine related.
 
I had it happen to a Beretta 92 previously. I happened 2 times with my CZ compact recently. The gun is new with 750 rnds thru it. The mags are stock OEM CZ and are clean and lightly lubed.
The gun is a carry gun...thus I must get to the root of the problem. It is the 9mm version, with the 10 rnd mags. I havent taken notice to whether it was one mag that was in the gun when this occurs. The ammo was Win white box and Talon 147 gr JHP. Thus my question. shoot well
 
I have thought of the reasons ..what could be to blame?
Ammo not having the force to send the slide to full lock and weak
return? Recoil spring whimped out...with occasional failures to return the slide /with bullet in chamber?

If it is a mag problem..what could it be? It seems to me if it was mag related, wouldnt it be more consistant.? The springs are like
1 ton truck springs, the followers are new and lightly lubed. Ammo slides in and out with no hang ups or problems.
If the spring binds up or hangs up in the mag...the gun will think its empty and lock the slide back....Is this what you are thinking?

One thing I didnt notice is when it happens If the slide lock it activated? I am always looking in the chamber checking for a
FTE not the other side of the slide. Never finding anything..I just rack the slide and load the next one.....

Well another excuse to go to the range and see if it does it again.
Any other thoughts.....? shoot well
 
Check the location of your thumb/fingers that may be anywhere near the slide release when firing. The size of the Compact and the location of the release could be causing you to push up on the release under recoil.

Obviously, could be a mag problem as others have said. Number your mags and see if any single one causes more malfs than any other. Take the one or two worst offenders and check for any differences between them and ones that don't fail. If you only have one or two mags, check for the clearance and slop near the slide release actuator inside the slide. Dremel or file the mag if necessary to give a little more clearance. That won't harm the function of the mag.
 
What I was thinking with regards to the magazine is premature activation of the slide lock. Something just slightly out of spec, for instance, that occasoinally hits it. The next time it happens mark your magazine with nail polish or something and see if any of the others do it.
 
I agree with Mal H. I ride the slide stop often with my Glock 19 causing premature slide lock. Watch your thumbs.
 
I had a CZ compact that did this with 147gr loads only. Didn't matter whose I tried. 115 and 124 loads caused no problems. Tracked it down to the nose of the round was, at times, hitting the slide lock. No rhyme or reason to when it would just happen. First round, last, in the middle of a string, a round would shift slightly and hit the stop. A little reshaping of the stop with a file cured the problem.

Months later a friends "new" Glock started doing the same thing with 180gr loads. Turned out to be the same problem. Must have happened to the first owner also, would helps explain the deal he got on it.:D
 
It would be good to know if the slide was being stopped by the slide stop/release or not.

If this is the case, 1: the spring that keeps the slide stop in the down position could be weak and allows the recoil to activate it even though there are rounds still in the mag. (147gr should be relatively heavier recoil-wise for standard pressure 9mm.) Or, 2: your thumb is inadvertently activating the stop/release under recoil.

If the slide is stopping somewhere along its travel between full lockup and slide locked back (as in an empty mag). Something is dragging it. Either a very strong mag spring that puts a lot of pressure on the round to be fed agains the feed lips or there is a burr or dirt between the slide and frame.

Since this has happened on both a 92 and a 75, my guess would be that your thumb is activating the stop/release or you don't clean your guns much (I'm kidding of course).
 
There is no spring holding the slide lock down. Its dynamics run off of the mag springs. CZ mag springs are like truck springs, very stout. But as long as the spring, follower and ammo are following their designated path, this shouldnt be a problem.

I took out the slide stop and checked it out for "friction or rubbing
marks"..I dremmelled it alittle and polished it wear it contacts the slide and wear bullets could hit it, just in case that is an issue.
I also polished the slide on the interior wall just in case it was hanging up there.

I cant rule out the thumb/hand hitting the release...but wouldnt this do the opposite..if I hit the button releasing the mag..it would drop down ...thus taking pressure or "unloading" the slide stop. What am I missing...anything?

I dont think I am limp wristing...although I was asked out to dinner by a guy about five years ago (sorry, couldnt resist!)
I havent had any trouble of this kind..thats been traced to improper grip/limp wristing. I have been analyzed by good instructers and they all tell me to work on my stance..thats it.

Any other suggestions.????????????????????????????????????

Shoot well
 
Many times people will fail to lock their elbow and although they believe they are not limp wristing the gun the failure to lock the elbow will cause the same problem. Couple this with a gun that is new and tight and is dirty from firing say a box or two of ammo and the slide occasionally fails to lock back.

Try thrusting your arm out straight and start with a clean and well lubed gun. Do not grease anything since you are having this problem, only use a good grade of gun oil like break free. Keep your thumb away from the slide release lever.

Make sure you are using full power ammo and not low power reloads or weak factory loads (they do exist).

Make sure the bullet weight is not on the light side (for example a 90 grain bullet) in a 9mm instead of the standard 115 grain or 124 grain loads.

If the problem still persists (assuming the gun is broken in) look for a mechanical problem.
 
Eric,

If your thumb is underneath the slide stop and pushes UP on the lever during firing, the slide stop will activate causing the slide to stay open. If you are using a 2 handed grip, your weak hand thumb might be hitting the lever during recoil.

Also, make sure that your ammo isn't creeping up toward the barrel. I had some magazines that would lock the slide back if the ammo was not fully seated to the rear. This problem was partially, my fault and partially a problem of the magazines being either dropped or knocked about during transport to/from the range.

my $.02
 
A couple of interesting ideas...I checked my off hand grip and find
it unlikely that my thumb is pushing up on the slide lock that hard..with my standard/usual grip my weak hand is well under my strong hand. I really dont deviate from it unless I am doing
it intentionally.

The magazine theory I will have to look at. I will check where my ammo is in the mag if/when it happens again.

The weak ammo is interesting also..would explain the win white box..but 147 gr Talons...size could be the issue there.

I have a wolf recoil spring on the way that will help a little with
this problem. And I think with everything that was polished as of
today...we may have it licked. ?

I will look at my grip...I dont think that is the problem..but has merit anyway.

Thanks for all of the advice and merry xmas
shoot well
 
This sounds like a slide release/grip problem. I've always had a problem with 1911's doing this. The problem is that I shoot left handed and under recoil my trigger finger will bump the release enough to JUST catch the edge of the slide release lock area in the slide. The slide release isn't fully engaged, just caught on the edge. A right handed friend of mine also has this happen when his thumb bumps the release.
This can be tough to spot, since the release doesn't fully engage.
Next time, carefully turn the gun over and see if the stop is up.

I've never seen a 'limp wrist' or strong mag spring cause the slide to just stop. Usually these will cause a double feed situation.

Since this has happened to two different brand guns, it's unlikely to be bad guns. I suspect that you've never had this problem on a handgun that uses a spring loaded slide lock.

This is a common enough problem, that Jeff Cooper taught shooters using the Weaver grip to hold the slide lock down with the thumb of the left hand, while shooting.
 
The beretta I shoot is my cousins and it hasnt done it to either of us in years. However that gun did it to both of us in the same day. He just kept shooting it and it hasnt done it since. He always blamed it on bad ammo.

I will watch my hands when shooting next time. I still dont think thats it..but hey, anythings possible.

Its gonna drive me nuts...gonna have to go shoot tomorrow. Just to see what happens.....thanks for the help. shoot well
 
This is just an idea but you might take a shooting partner and let them run the gun,this would give you a chance to see what could be causing the problem, and to see if it is in fact you or the gun. Take several types of ammo and some white tape to mark your suspect mags and i think you will find the problem. good luck
 
i had this problem witha cz85

Eric,
There is a slide stop spring in the cz. It looks like a question mark. It is located around the slide release. If the spring is slightly bent, (relieving tention) the slide stop will engage. I had this problem with my cz. It helped a little, however the problem lessen even more when i had cz send new mags. They have 2 different followers. The newer ones worked much better. My gun origionally jammed 1 out 10 rnds, After swapping out the slide stop spring, changing the mags and polishing the ramp, I got it to 1 or 2 out of 200 rds. Stillwasn't good enough for me.. Sold it and got what I wanted in the first place. a 228 :D :D :D
 
I think , well I am sure I found the problem. The cz barrel has a single upper lug. This fits up in the slide in serrations or grooves.
The barrel had a bur on the muzzle side of the lug, on top of the barrel. It was catching intermittenly on the slide. I carefully got
rid of the bur and polished the barrel. Feels like its fixed but I wont know for about another 500-1000 rnds...I had it checked out
by a good semi smith and he caught it. Thinks the barrel is too soft.....will have to investigate...thanks for the replies and shoot well.
 
You must log in or register to reply here.
Back
Top