spacer for Single action mainspring?

[jimster]

I wasn't sure what catagory to ask this, but I'll try here, even though the topics in here are much more complicatied than this question.

I want to lighten the mainspring a little bit on my USFA single action army clone, and have read where sometimes they put a spacer between the mainspring and the frame. I don't want to get another mainspring, and I'm happy with letting the rest of the gun parts break themsleves in, but just wanted to lighten that mainspring up just a little bit (and still pop the primers)...

So, for those of you who have done this, what materials have you tried, and how thick of a spacer would ligghten it up just a tad....
and...if this is not recomended....tell me that too.

I didn't want to change much in this single action, until such time as the original parts/springs wore out from use...just want a little bit lighter mainspring.

Any comments are welcome....hope I posted this in the right spot, thought about "Cowboy action shooting" or "single actions"....
but I think this falls under gunsmithing....

Thanks a bunch

[gunnut69]

I've done this and have used a lot of different materials, those miserable TEMPORARY credit cards that come in the mail, DAILY, and brass shim stock. Nearly anything will work that will remain stable over time but shim stock or brass flat is likely the best. That said you probably won't be too happy with the results.  The best method is to grind or hone the spring to produce less thrust. Occassionally a spring is ruined (several the first few times) but that usually give the best pull. Brownells lists several in their catalog that are reduced but also re-engineered to produce better pulls and still fire the primer. Also,, note that primers are different in hardness. What might fire one brand will cause a lot of missfires with another. Also too light a hammer strike will sometimes cause erratic ignition and degrade accuracy. This last is not too much of a problem with the Model 'P' as the hammer is so heavy..

[jimster]

It sounds like I'm better off getting a mainspring from Brownells since I'm not very good at grinding or honing things. I think i'll try one of the reduced ones.

Thanks for your input on this, much appreciated.

[gunnut69]

When working the trigger on a single action or rally any pistol [polishing the parts will likely produce the best results. Any part that rubs another or is rubbed by another part should have that junction smoothed,. DO NOT renove metal,,just polish and smoth a bit.. Stones work best(either hard  Arkansas or my preference synthetic/ceramic) but good results can be had by using extremely fine water proof sanding paper.. Start with 600 grit or finer and 1000 or even finer are excellant.. Be sure to use water to lube and with a backer to keep square edges square and flat places flat! Shims can be used to limit lateral movement on pins containing rotating parts and use a good dry lube..  DO NOT change any angles, especially the sear interfaces as this can create a dangerous situation!!  Smoothing the operation will also have the added benefit of allowing the lighter mainspring to provide more energy to the hammer as less is lost overcoming drag.