Kimber mainspring

[redlightrich]

Hello all. I am trying to figure out the stock mainspring weight on a full size ( 5") 1911 .45acp made by Kimber. I have some very conflicting info.
Wolff lists it as 21lbs
I thought most 1911's had a 23lb
Kimber customer service says they are and were 18lb?

As you can tell from me writing this post, I don't trust the customer service people at Kimber at all. 18lbs sounds low for a .45 acp, but I guess it is possible. That sounds more like a 9mm MS?

Does anyone have real data for me?

Ty

Rich

[Steve in Allentown,]

Originally Posted by redlightrich

Hello all. I am trying to figure out the stock mainspring weight on a full size ( 5") 1911 .45acp made by Kimber.

Standard strength mainsprings are 23lbs.

Wolff lists it as 21lbs

I may have missed something but I think you're referring to Wolff's recoil spring for the Kimber.

Kimber customer service says they are and were 18lb?

Obviously, you can swap out mainsprings but for a .45 always start with a 23lb mainspring. Also, start with a 16lb recoil spring for a 5" .45. Recoil springs can also be swapped to suit the ammo being used. Manufacturers often use 18 or 18.5lb recoil springs as a substitute for quality control.

18lbs sounds low for a .45 acp, but I guess it is possible. That sounds more like a 9mm MS?

I have a 5" 9mm that is tightly fit and has Acc-u-rails. That's a lot of resistance. To get the slide to move fully to the rear I had to use a 16lb mainspring and a 9lb recoil spring. The point is, no matter the caliber of the pistol you can use various combinations of the mainspring and recoil spring to tune the functioning of the pistol. But first establish a baseline using the standard spring weights then experiment.

[georgehwbush]

i'm not a pistol person, but my acp45 llama 1911 knockoff only has one spring, is it missing something ?

[Aguila Blanca]

Originally Posted by georgehwbush

i'm not a pistol person, but my acp45 llama 1911 knockoff only has one spring, is it missing something ?

It isn't, but you may be missing a spring: the main spring in a 1911 is the hammer spring. The spring that rides beneath the barrel is the recoil spring. That's NOT the "main" spring in a 1911. There's also the sear spring. If you have an external extractor, there's also a spring beneath that. And there.s a tiny spring inside the magazine catch assembly, and another inside the plunger tube.

Your Llama has a lot more than one spring.

#17 is the main spring.

[redlightrich]

Thank you all for contributing. I am not trying to tune my gun per se, I just wanted to know if anyone has a clear answer.

My question is:
What is the factory installed mainspring ( hammer spring) weight on a Kimber
5" 1911 in .45acp? I can easily get the mainspring in my hand, but I have now way to accurately test.

Thank you for any help you can provide

Rich

[AL45]

What I can say about the matter is that my brother has a Kimber 1911, my son has a Ruger 1911 and my wife has a Sig 1911. My .45 ACP reloads work fine in the Ruger and Sig, but will not work the slide in the Kimber.

[Lurch37]

Midwest sells a Wilson reduced power 18lb, a Wilson reduced power 19lb, a Wilson USGI style 23lb, and Wilson extra power 25lb.

For Colts, Wolff's website lists 15lb thru 21lb as reduced power, 23lb standard, and 25lb thru 34lb as extra power. It also lists a 21lb mainspring as factory from Kimber.

I am also of the opinion that the standard weight of the hammer spring in a 5" Govt 1911 is 23lb with a 16lb recoil spring.

Kimber's website sells a 3 spring kit with only the recoil spring weight given, (16lb).

I read a 2012 thread on 1911.org that says that Kimber puts in 21lb hammer springs.

As the above shows, there are many options to your question.

Although the Kimber rep said 18lb, that seems light to me. I have yet to find any specs on a Kimber mainspring weight from Kimber themselves.