Kimber Micro 380 slide stuck open

[FergusonTO35]

I don't say the R-word when talking to gunmakers. The gunsmith called Kimber about it and they said that, if there is nothing broken and this is the only time the gun has malfunctioned in this way, there is probably nothing they can do. So, I told her to give it a good inspection and test fire just to be sure. I'll probably replace the rear plate, firing pin, and firing pin spring for peace of mind.

[shooting on a shoestring]

If it were mine, I’d use a dot of JB Weld when putting it back together. The next time disassembly was required, a touch with a soldering gun would be the key to unlock it. If that sounds to drastic, locktite or even fingernail polish could ease your mind.

[FergusonTO35]

The 'smith cleaned and inspected the Micro, then fired a box of factory ball and a box of my reloads with no problems. I think I am going to replace the recoil spring and firing pin spring since it is about due for them, might replace the firing pin plate too. Then shoot it some more and, if no further problems, chalk it up to just one of those things that happens.

[Boogieman]

Any thing that would slow the firing pin returning could cause this. I would check for trash in the firing pin channel , or a bent pin.

[FergusonTO35]

Thanks, will do. The OEM firing pin spring is noticeably shorter than the same from either Wolff or Sig Sauer. The Kimber firing pin is identical to Colt, the only difference in the Sig Sauer pin is that the slot in the full diameter center section is more narrow on the Sig. The Sig or Wolff firing pin spring is noticeably harder to install than the original, however it will still propel a Bic ink pen out of the barrel no problem. Right now, I'm thinking the original firing pin spring was marginal and did not return the rear of the firing pin into the plate all the way. When the slide came back, friction from the hammer being cocked pulled the plate down and jammed the gun. Hopefully I can shoot it soon.

[Boogieman]

A new spring sounds like a good idea. This is not unheard of in 1911s , same style, For a short time during the firing cycle the spring is the only thing holding the plate in place. The spring also helps keep the firing pin from contacting the primer if the gun is dropped barrel down.

[FergusonTO35]

Well, I was able to put 40 rounds through the Micro today and am happy to report the slide plate stayed in place just fine. Every round went bang, firing pin indentations were as deep as before. Talked to my BIL, who is career military and a real 1911 freak. He said he has seen this kind of failure before, and it was always from a damaged or worn out firing pin spring.

[Boogieman]

If the OEM spring is shorter than a Wolf your problem was most likely a worn or bad spring.

[FergusonTO35]

Yes, the OEM spring is shorter than both Wolff and Sig. I'll try to post a pic.

[FergusonTO35]

Put more rounds through the Micro today with no problems. I 'spose I'll put it back in the rotation.

[Lefty Red]

One thing I don’t like about the Micro 380 is the recoil spring is hard to upgrade. The Micro 9 was easy to get an extra power spring. Seems like you have to “hand cut” a Micro 380 to fit.

Lefty

[FergusonTO35]

Really? The Wolff extra power spring fits mine perfectly, as does that of the Sig P238.

[Lefty Red]

I meant the extra power springs. I was wanting to use the Underwood +Ps in the Micro.

Lefty

[FergusonTO35]

I have the Wolff extra power springs and they fit just fine. Mebbe yours were packaged wrong?

[Lefty Red]

Always possible or I got the 9mm’s spring mixed up with the 380’s when I stored them. But the recoil spring is about the only thing I change on my SA Micros.

Either way, it runs great and won’t get beat up with my carry ammo!

Lefty