SliXprings Firing Pins SliXpins 1860 Henry, 1866 &1873 Rifles Instructions

Stonger, Longer & More Durable Replacements for
1860 Henry, 1866 & 1873 Rifles
(This Slixpin is best served when installed in a rifle that has been Tuned and Lightened)
If you have a little or no idea how these firing pins are supposed to look, fit and work, STOP, get help or find someone who does know how to shape, fit and install them. Due to all the variations in machining tolerances on the different rifles and bolts this in not a "one-size-fits-all-perfectly" drop in set. It may/will take some individual fitting. Try all the fitting before you do any modifications.
1. Disassemble the rifle to the bare bolt.
2. Insert the new SliXpin in the firing pin bore of the bolt and measure how far it extends beyond the face. IF the pin does NOT extend to your liking, then you will have to counterbore the bolt bore. You can use a #6 drill bit to deepen the bore of the bolt to the appropriate depth so the pin will extend the proper amount. Be certain the pin shoulder will fall below the face of the extension counterbore. This means that with the firing pin extension in place firmly against the inside shoulder in the bolt, the firing pin will still have end play!!! Do not let the firing pin shoulder inside the bolt serve as the stop for the hammer fall!!!
3. Insert the SliXpin with the spring installed in the bolt and measure it again. If you have a lighter hammer spring, some extra extension MAY not be critical, but you will want at least .050" (but not much more than .060") protruding (your mileage may vary). IF, with the spring attached, the pin does NOT extend enough, then you will have to counterbore the bolt spring bore or shorten the spring a couple coils. You can use a # 20 drill bit to deepen the bore of the bolt to the appropriate depth so the pin with the spring will extend the proper amount, but still have the tension enough to retract the pin. 
4. With the SliXpin and spring installed in the bolt, insert the firing pin extension rod into the bolt bore and push the pin against the spring and stop; now measure how far the pin nose extends. If it extends too far, remove the SliXpin and remove material from either end, starting with the BUTT end until you get the desired dimension. However, if you wish to re-profile the nose of the firing pin, do that before dressing any off the butt end. (here, after you re-profile the nose, you may get it too sharply pointed and may need to re-dress it flatter, or radiused, and you may need all the extra butt length to keep it at proper length.
5. Now fit the cross pin, or return cam, through the bolt and retain the firing pin extension and repeat the test measurements in step #4. AND, now release the pressure and be certain the firing pin returns to battery and does not protrude in front of the bolt face. If all looks to your liking, completely re-assemble the rifle and double check that the levering action returns far enough to cock the hammer past the sear engagement and that during the closing cycle the firing pin does not extend past the bolt face.
If things aren't looking right, reread the bold face note at the top, heed the warning before any additional fitting or adjustment.
Good Luck and enjoy your shooting!