Kimber Ambi Safety Quality?

[Joshua M. Smith]

Hello,

I ordered a Kimber ambidextrous thumb safety. I'm left handed, and this will be replacing an STI ambi thumb safety on my carry weapon.

It was a tossup between King's and Kimber due to a unique design feature shared by both, and King's has been supplying the military and are constantly out of stock, so Kimber it was.

It's due to arrive tomorrow.

My question to you all is this: Have you experienced any problems related to the Kimber ambi safety, and if so, what was the nature of the malfunction and approximate round count?

Thank you,

Josh <><

[DefensiveCarry.com]

[wagglebee]

Kimber is metal injection molding. I would see if I could return it and get one from Ed Brown or Wilson Combat.

[Joshua M. Smith]

From what I understand, those are MIM too. The only one I'm aware of that is not MIM these days is the one I have - the STI/SVI.

I'm avoiding the tab that goes under the grip panel in favor of the modified tongue-in-groove hammer pin and cutout.

Thanks,

Josh <><

[wagglebee]

I wasn't aware that Brown and Wilson were MIM, but you may be right. You might want to call Brownell's and ask them.

Otherwise, the only real problems I've heard with the MIM is if you drop the gun or are rough on it.

[Joshua M. Smith]

Correction: Wilson is MIM, Brown is not.

Josh <><

[wagglebee]

But the Brown is the different style I believe. However, they are the same price within a buck or two.

[Joshua M. Smith]

Brown still uses the ear that goes under the grip. I checked. My only options were Kimber or King's (King's being preferable.) Mueschke makes one that is retained by the sear pin, but they have notoriously poor quality and the sear pin design is already weak.

Doing some more research, it appears Brown uses Investment Casting, which is somewhat similar and creates its own set of problems - air pockets and such.

MIM is about 80-90% as strong as forged, and if it fails, it will fail within the first few uses.

Kimber uses MIM almost exclusively, as does Wilson. The STI Spartan uses an MIM frame and forged slide and barrel (actually made by Armscor).

MIM is in more gun stuff these days than I'd care to guess at. The process has improved to the point that it can replace the old forgings. I'm not saying it's desirable or undesirable, but rather how it is.

I've only come across two failures of Kimber safeties on an extensive Google search, and one of those involved a solid knock which would have likely broken a forged safety as well.

MIM doesn't lend itself to "springyness" as does forged, but that's a small matter as long as parts fit tightly and a lighter safety spring is used (generally recommended for ambi safeties anyway...)

I guess we'll see how it does. If it doesn't do well, it'll get shipped back for warranty coverage. Their service bites (took them too long to send me the trace number on the order - had to bug them) but I don't let things go.

I tried a friend's subcompact Kimber outfitted with this safety, and it feels like it does fit as it should.

We'll see I guess.

Josh <><

[Joshua M. Smith]

Correction: MIM is now claimed to be around 98% the strength of forged, with cast being least desirable for quality due to the probability of flaws.

Josh <><

[wagglebee]

Correction: MIM is now claimed to be around 98% the strength of forged, with cast being least desirable for quality due to the probability of flaws.

If MIM is actually 98% as strong as forged, I can't imagine that there would be anything to worry about.

[mike benedict]

MIM parts on Kimbers break all the time Really not to well done

Having shot 1911s for 30 years the Brown ambi is the best I have ever used and I have not had one break

[Rob72]

Josh, as you are a lefty, I would really suggest calling Cylinder & Slide (or pick your custom smith) and spend the $$ to have a custom lefty safety made. All ambis suffer from the dovetail joint loosening up over time.

This could be remedied by using a regular safety with an extended shaft and squared, tapped end. Your left thumb tab- a plate with square cut hole- would would press over the squared end, and be held by (we'll say) a 2-56 or 3-48domehead allen screw. Hey, it's only money, right...?

[Joshua M. Smith]

Thanks folks.

Mike, I've seen one break under normal use. Anything can fail I guess.

The safety is supposed to be here sometime today. I'll keep my STI safety around just in case, but hopefully it won't be needed.

We'll see.

Josh <><

[rodc13]

I have ambi safeties on both my Kimbers -- Ultra CDP II & Desert Warrior. Never a problem with them, or anything else.

[Kerbouchard]

Josh, thanks for the post.

It's ironic that you were the one who asked for advice and I would venture to guess that most of the people who read this thread will learn from you.

[Joshua M. Smith]

Thanks folks.

It got here today. I installed it. It took no fitting to the sear - Kimber molds them pre-fit to guns which are in spec.

Compared to the STI safety, it feels and looks cheap. I had to take a lot of flash off and smooth down rough spots to keep it from binding. I also had to take the slop out of the joint.

BUT! It's on now, and is performing well. MIM parts will fail early on if they're going to fail, but flipping it on and off 100 times as well as 50 rounds or so through the gun didn't reveal any further flaws.

I really wish I could have gotten a King's as the concept is great IMO, but Kimber's execution leaves something to be desired.

I'm keeping the STI safety as a backup, but with a light spring on this one I don't think it will fail.

Here's some pics; excuse the scratches. They're from the STI safety before I got things smoothed down on it. Need to buff them out now that they're visible I guess.

Josh <><