Lighten trigger pull on new 1866 Uberti Yellowboy Short Rifle

[Teton Tim]

I have a new 66 Yellowboy rifle and the trigger pull is about 5 lbs. I would like to lighten it to between 2.5 and 3 lbs. Can this be done by modifying the main spring? The spring seems pretty heavy and I'm wondering if cuting a slot in it like you can get with aftermarket main springs for a Colt Clone SAA would work. Or does it require adjustment to the trigger/sear?

Any help would be appreciated.

Thanks,

Teton Tim

[Nine Toe Jim]

I have an Uberti Yellowboy that I picked up in new 1986 and it had a very strong mainspring. Recently I had a gunsmith order me a new spring and told him I would like it lightened. He narrowed the spring from both sides instead of putting a slot in it and it sure made a difference in the action of the gun. I've never had a malfunction since I changed it.

[Delmonico]

I don't know if I would trust advice on trigger lightening from a guy named Nine Toed Jim.

Sorry Jim, I could not turn that chance down.   Have a wonderful day.

[Nine Toe Jim]

OOPS. You might just have something there Delmonico

[Terry]

There is a mainspring tension screw on '66's.  I didn't care for the stiffness of the Mainspring in mine either, so I just backed the adjustment off...

[Marshal Will Wingam]

I've had the trigger spring on my 73's narrowed a bit. Seems to be the hot ticket. The mainspring can be adjusted lighter without putzing with modifying it.

[Marauder]

Another trick on making the spring tension lighter is to do as they did with the old Colt SAS's - put a thin washer between spring and the frame.  Take the screw out, lift out the spring, the put washer next to the frame and put the spring back in.  If you don't like it - it's easily removed.

[Marshal Will Wingam]

Another trick on making the spring tension lighter is to do as they did with the old Colt SAS's - put a thin washer between spring and the frame.  Take the screw out, lift out the spring, the put washer next to the frame and put the spring back in.  If you don't like it - it's easily removed.

Aw heck, that's way too simple. I have a Colt with the original (somewhat) leather spacer under the mainspring.

[Delmonico]

Ok I got one for you ta ponder, I have a Savage 99 with the trigger return spring shimmed with a plastic washer.  The plastic washer is the one that is used on the screws that hold the gas gauge sender on a VW beatle to the tank.  Never know hat you'll find in the junk box when the need arises.

[Driftwood Johnson]

I strongly suggest you don't mess with the hammer sear engagement. Unless you know what you're doing, it's easy to ruin it or even make it dangerous. My '73 has basically the same hammer trigger arrangement as your '66. I bought it used and the previous owner had done a chop job on the trigger and ruined it. It was unsafe and I had to replace he trigger and hammer.

Reducing the strength of the hammer spring will have an effect on the trigger pull by reducing the amount of friction the trigger has to overcome to release the hammer.

You won't have much luck cutting a slot in your spring, those are done before the spring has been hardened and tempered. You won't have much luck cutting through the hard steel and controlling the cut.

Putting a shim of some sort under the spring will help some. More effenctive is regrinding the spring to a 'wasp waist' shape, or hourglass shape. If you're very carefull, and go slow, you can do this yourself with a Dremel tool and the smallest grinding wheel you have for it.

A few cautions: Hold the spring in your hand while grinding so you can feel how hot the spring gets. Dunk it in water after every stroke to keep it cool. If it gets too hot to hold you will probably ruin the temper, but you can keep it cool by holding it in your hand. Keep all grinding marks along the length of the spring, do not go across the width or thickness. Most Uberti springs have some tooling marks across the face. Theses are excellent stress risers for the spring to break at. The original spring on my '73 snapped in half halfway through a match one day, right on one of those tooling marks. Carefully grind them out with your Dremel tool, working along the length of the faces so that the new tooling marks you leave behind are lengthwise, not across the spring.

Lastly, when you are all done, go over all the edges of the spring with the finest files and stones you have to round off and relieve any sharp edges or burrs left behind. Sharp edges and burrs are places that the spring wants to break at when stressed.

I suggest you order a spare spring from VTI or somebody to work on, so that in case you go too far you can still put the original spring back in.

Go slowly and keep trying your results until you achieve the hammer stroke and trigger pull you want.