1911 mainspring?

[GoodOlBoy]

Again Colt '70s model Mark IV what poundage Mainspring should I look at?

GoodOlBoy

[Adam Helmer]

GOB,

Are you talking about the "Recoil Spring" that goes under the barrel betwixt the plug and recoil spring guide? I have used the 18 pound and 20 pound recoil springs in various Colts.

Adam

[Jack]

If you're talking about the recoil spring under the barrel, as Adam has described... I believe the Mil Spec is 16.5 pounds.
I keep an 18 pound spring in mine.
If you shot nothing but target wadcutters, you might go to a 13 pound spring- but ONLY for wadcutter loads.

[GoodOlBoy]

no the mainspring is in the mainspring housing setting under the mainspring cap which pushes upon the hammer strut, which is connected via the hammer strut pin to the hammer which when the trigger is pulled is released by the disconnector via the sear causing the hammer to strike the firing pin and making the gun go boom.

IE What poundage mainspring? Any ideas? I have never replaced a mainspring before but in this particular gun it don't have enough umph to make nitro go boom, much less a primer.

The Reason I ask is because Midway offers Mainsprings from 15lb up to 34 lb and does not indicate the standard poundage of a 1911A1 mainspring.

Anyway I appreciate the responses guys. . . . Any ideas about the actual mainspring?

Thanks

GoodOlBoy

[Jack]

I have no idea what a stock mainspring poundage is.
Check with Brownells- they stock Colt parts, I think. You might be able to figure out what the factory spec is from them.

[GoodOlBoy]

Appreciate the idea Jack. Unfortunantly, neither they, nor Midway, nor Numrich indicate what the stock spring is. . . . I will keep looking.

Thanks

GoodOlBoy

[Jack]

GOB, I just remembered that I have a copy of Layne Simpson's book, The Custom Government Model Pistol.
In case you aren't familiar with the book, it discusses in detail modifications and 'go fasters' for 1911's.
Anyway, Appendix 3 in the book is 'Factory Standard Spring Weights'.
He lists: Hammer Spring (Mainspring) 23 pounds.
The weight is the same for the GI model, the Commander, and the Officer's Model.
Hope that helps.

[Adam Helmer]

GOB,

Let us go back to the beginning. A Colt 70s Mark IV Mainspring, you say. Ok, did you once-upon-a-time have such a spring? LOL. Did you contact Colt about same? Again LOL. What did Colt have to say about such spring, poundage wise?

You are correct, GOB, it is a "Mainspring" and not a "Hammer Spring" as I assumed. My fault. I would ask Colt and then go with whatever they say is "Good-to-go" in the Mark IV. I may have a GI mainspring someplace hereabouts and if I do, I will send you a PM. Be well.

Adam

[Lycanthrope]

22-24lb is pretty stiff and will light even high primers (I believe 22 is factory). I've run 19lbs for years to reduce trigger pull and they light everything except high CCI primers. 17lbs will occasionally fail to light CCI , but will light Federals.

Remember, that the mainspring will soak up some of your slide inertia and going too heavy can cause failure to extract with lighter loads.

[GoodOlBoy]

Ok Got one from Ed Brown on order, thanks guys. Colt was about as much help as an ulcerated molar. Every time I asked them a question they pointed me to the web page for their custom shop. . . . .

Anyway thanks again

GoodOlBoy

[Craig 522]

I run 15 lb in my guns unless using hard (as in CCI) primers. Then a 17 lb would be used. However, I never use CCI primers so it's a non issue.

Granted my 1911 type guns are far from stock so your results may vary.