This mainspring system is a replacement of the standard Uberti hammer and mainspring. Unlike the standard hammer which is a case hardened mild steel material, our hammer is made from a hardened stainless steel. It has a unique design adapted from the 66 style hammer which allows for easier, smoother more reliable locking of the action with a none wearing surface with improved striking ability.

Package includes:
1 x Hammer
1 x Grub Screw
1 x Hardened Strut
1 x Light Coil Spring
1 x Extra Light Coil Spring
1 x Brass Strut Stop
1 x Shorter Mainspring Screw
1 x Red Grommet
1 x White Grommet
1 x Allen Key

Fitting:

The new style hammer comes with adjustable sear engagement grub screw which can be adjusted for a lighter trigger and to remove creep we recommend the use of 243 Blue locktite on the grub screw.

The hammer is replaced by removing original hammer via drifting out hammer pivot pin and replacing with the new hammer.

The coil springs are simply inserted onto the strut and captivated by a pin, (which is not supplied) through the rear hole on the strut compressing the spring.

The brass strut stop is fastened to the trigger/hammer assembly with the shorter screw provided in the kit. This replaces the existing mainspring screw and also requires the removal of the front adjustment screw. The strut is simply put with the forked end against the hammer strut recess and the other end inserted into the brass stop. Slowly pulling the hammer rearward to release some of the pressure and removing the pin in the strut. Now the hammer can be put in the full cock position for re-assembly.

There are 2 grommets provided in the kit the spring can be tuned several ways

1 - We recommend for the lighter strike, for such as Federal primers, use the white grommet be placed on the strut with the collar in the forward position, with the xtra light spring. The pin can than captivate the spring in the same as above instructions.

2 - The 2nd tension would be replacing the white with the red grommet and the extra light spring.

3 - The 3rd tension is removal of both grommets and replacing the light spring with the heavier spring without any grommets.

4 - The 4th tension is placing the white grommet in front of the heavier spring

5 - The 5th tension is replacing with the red grommet with the heavier spring. This would only ever be needed if you were using a CCI rifle primer over a pistol primer.

This system provides a more positive and reliable striking system for the junior through to the competitive shooter who might overrun the hammer and who is looking for a quicker lock up time. The coil springs are more consistent and snappier than a leaf spring which can become lazy and fatigued after a period. This kit is complemented by the use of our replacement firing pin and spring (sold separately) which is designed to work in conjunction with this system.

We also recommend that if you are using the original factory firing pin and spring you should replace the firing pin spring with a lighter spring (also available separately).

Although this system is designed to be a drop in kit we recommend it be fitted be a competent Gunsmith.