Weak mainspring (?)

[jonk]

I have a Pietta smith. The thing needs almost no effort to cock back, sometimes doesn't set off the cap (maybe 1-2X per skirmish) and the hammer bounces on falling. Am I to presume this is the mainspring? I have a replacement I could pop in... or could/should it be bent or shimmed or something?

[Mike Rouch 07791]

Pop the new one in. That will take care of your problem unless your new one is weak too.

[jonk]

Yeah, I'll probably do so. The old one is still ok for a spare emergency one, but you should need more than 3 oz of force to cock back a hammer...

[Curt]

Hallo!

Due to the lack of Italian Quality Control, one can get a rubber spring or one so hard to snaps after a few uses.

I do not know your skill level, but a "too soft' spring can be rehardened/tempered by heating, quenching, and then drawn down in a kitchen oven for a few hours.

I have heard, but never done it myself to know for sure... that a 'nut' placed under the mainspring screw can increase the height and therefore the tension on the spring. (I no longer have a repro Smith to test the theory either...)

Curt

[jonk]

That's strange... Pietta is one of the better repro makers I think, and Italian guns in general (can) be of very high quality.

I'll skip the re-temper. I just did a little reading on it and it seems like it COULD work... or not. Luck of the draw without a thermocouple and such.

I'll pop the new one in later today and see what happens.

[Eggman]

I had the same problem with a Rogers and Spencer revolver. I described the mushy spring problem to Bill Osborne and said I wanted the best replacement spring he has. He sat down and tested the spring tension of ten or fifteen springs over his knee and then handed me the "best" one which has performed perfectly (absolutely no misfires/no set-backs) ever since.

[Maillemaker]

I re-tempered a spring in my Richmond Carbine. It is not hard if you are careful, but I would not try it without a spare in case you screw it up.

Heat that sucker to bright glowing heat and quench. Then polish it, and re-heat it until it turns a dark blue. For a more aggressive temper, you can soak it in your molten lead pot. This will result in a softer spring.

Steve

[jonk]

Just had it apart. Turns out the screw that anchors the spring to the receiver had just worked loose. :)

[Curt]

Hallo!

Aha!

Lends some credence to the old addage about the gun is fine, but it's the loose screw (or nut) behind the trigger that is the problem.

:) :) :)

(Pietta, when they started circa 2000-ish were so bad the Horror Stories abound and almost drove them out of business. They regrouped and came back at it, IIRC, circa 2003/2004 and do okay now- much. much better than at first. Much can still depend upon the one in your hand at the moment versus another one- especially if my Theory holds true that importers contract for different levels of QC needed by their business model/profit margins. Say a Cimmaron Firearms versus Cabela's.)

Curt

[Mike Rouch 07791]

Maybe you can borrow some lock-tite from Ian???

[jonk]

I always have loc-tite with me. :)