Slide releasing when magazine is inserted

[JPA]

My Kimber Gold Match II has approximately 3000 rounds through it, and recently an issue developed. When the slide is locked back, and I insert a full magazine, the slide with drop automatically from time to time. It doesn't always happen, but it happens more frequently when shooting USPSA than it does at the range.

I called Kimber, and they sent out a free slide stop. I haven't shot a match with it yet, but while inspecting my gun more closely, I think I might see the problem. Does the notch in my slide appear correct? The lower part is rounded off, and I noticed that when I use an empty mag and pull the slide back, the slide stop only goes about half way into the notch. So, I suppose my questions are:

1) Should the slide stop fully engage the notch in the slide?
2) If so, what would cause this?
3) Can it be fixed?

I will be out of town for the weekend, so I may not get a chance to reply until Sunday. Thanks for taking a look.

This is what the slide stop looks like when locked back on an empty magazine:
http://i234.photobucket.com/albums/ee221/gunsandmotorcycles/kimber_2.jpg

This is what the notch on my slide looks like:
http://i234.photobucket.com/albums/ee221/gunsandmotorcycles/kimber_1.jpg

[niemi24s]

The slide stop's not going up far enough. It should go up at least 86% of the way into the notch. It's probably kept from doing so because the slot on top of the slide stop is not deep enough.

With the gun configured just like in your top pic, push up on the slide stop. If it doesn't go up any more, the condition in the first paragraph is confirmed and the notch in the SS needs to be deeper.

The aft, outer portion of the slide stop should go up into the notch in the slide at least 0.089 inch becasue that's the minimum depth of the slot (see M1911 Full Blueprints, our Tech Issues section). The aft end of the slide notch should be between 0.086 and 0.104 inch high.

If, however, the slide stop can be pushed farther up into the slot, the cause is either the magazine follower or the part of the SS the follower contacts.

[JPA]

The slide stop's not going up far enough. It should go up at least 86% of the way into the notch. It's probably kept from doing so because the slot on top of the slide stop is not deep enough.

With the gun configured just like in your top pic, push up on the slide stop. If it doesn't go up any more, the condition in the first paragraph is confirmed and the notch in the SS needs to be deeper.

The aft, outer portion of the slide stop should go up into the notch in the slide at least 0.089 inch becasue that's the minimum depth of the slot (see M1911 Full Blueprints, our Tech Issues section). The aft end of the slide notch should be between 0.086 and 0.104 inch high.

If, however, the slide stop can be pushed farther up into the slot, the cause is either the magazine follower or the part of the SS the follower contacts.

Thanks for the detail. I am able to push the slide stop up farther manually. Now that you mention it though, my mags have a few thousand rounds through them and are on the original springs. I also always keep two of the magazines loaded, which wouldn't help. I should probably swap the springs out and see if that solves the problem. Would you have any recommendations for springs? The magazines are KimPro Tac if that makes any difference.

Thanks!

[niemi24s]

New springs might help IF the current ones are so weak they can't push the follower up all the way. I can't imagine a spring getting that weak, however.

Suggest you remove the slide & barrel and re-install the slide stop. Then, insert a magazine and see how far it pushes the back end of the slide stop up in the frame hole. It should go all the way up.

If it doesn't go all the way up, you should now be able to look and fiddle around and find out why.

[sevenL4]

I have a 70 series Colt that has probably 50,000 rds thru it and a Systema that I have put 20,000+ thru. Both of them show a higher cut for the stop to engage and neither shows the deformation yours has. On the Systema it clearly shows that area has been hardened. There is a slightly different color on an area smaller than a pencil eraser at the rear portion of the slide stop cut. Maybe you could send Kimber the slide and have them cut the slot correctly and harden it.

[JPA]

Thanks for all of the replies.

I got a new magazine (KimPro Tac), and the problem does not happen with that mag. The two magazines that this "half-engagement" issue happens with are also KimPros, with probably 1000 rounds each through them, and are stored with the gun loaded.

When I push the follower down on the two older mags I can tell that the spring is softer, but those are also my two most reliable magazines - never once having a feeding problem.

I know that the brand new magazine forces the slide stop fully into the notch as it should, but does that necessarily mean that the softer springs are too soft? I'm wondering too if after the first couple hundred rounds, that this magazine won't have the same problem.

[niemi24s]

Wolff extra-power magazine springs are cheaper by the dozen.

[JPA]

I just ordered a 3 pack of the Wolff +5% Extra Power springs. Spring tension appears to be my problem, and going a little stiffer sounded like a good idea.

I suppose I'll see how long it takes for this problem to surface again. If I have to replace the springs in my loaded magazines every year, I'm okay with that. If a couple weeks of pressure on these springs causes this issue to surface again, I'll send the slide back to Kimber.

Thanks for the help

[hutch1510]

I have a 70 series Colt that has probably 50,000 rds thru it and a Systema that I have put 20,000+ thru. Both of them show a higher cut for the stop to engage and neither shows the deformation yours has. On the Systema it clearly shows that area has been hardened. There is a slightly different color on an area smaller than a pencil eraser at the rear portion of the slide stop cut. Maybe you could send Kimber the slide and have them cut the slot correctly and harden it.

i dont think it was hardened, but rather "annealed" this changes the color, and actually softens the metal to keep it from cracking.