Problem with Sharp-Tail 12 ga SxS undocumented design change

[ppeeks21]

I need to talk with a tech person about the current version of their Sharp-Tail 12 ga SxS Coach Gun. I'm going to reduce the hammer spring strength, but the gun I just bought includes a design change to the hammer spring that is not documented anywhere, as far as I can tell. Other Sharp-Tail owners I've shown photos to say that their guns do not include the design change.

Huglu has replaced the simple "hammer spring on hammer spring rod" with a subassembly in which the spring is captive on the spring rod, with a slidable collar and fixed end cap on the end of the spring rod. The collar, instead of the free end of the spring as in the original design, now fits and sits in the hammer spring plate, with the rod free to slide back and forth through the collar. This subassembly is not shown in any CZ parts diagrams or lists. It makes shortening the hammer spring a much more complicated task.



More specifically, I cannot readily see how the end cap is connected to the end of the spring rod. Is it crimped? Is it threaded? Is it press-fit? I would like to know how it is connected before attempting to separate it from the rod -- if it is even possible -- in order to get the spring off for careful, incremental trial-and-error length reduction. One gunsmith I've consulted thinks that CZ would not design a subassembly that cannot be disassembled, but I'm not as confident in that point of view. They may want the hammer spring assembly to be replaceable only as a single component.

If anyone knows someone who might know something about this, a lead would be greatly appreciated.

[ppeeks21]

OK, well, I have my answer and it isn't what I was hoping for.  I spoke with a technical rep at CZ-USA.  The design change is recent and all Sharp-Tail SxS guns going out the door have the new captive hammer spring subassembly.  He believes that the change was made due to reliability issues with the original simpler design.  Frankly, I can understand that reason.  However, the end cap is permanently attached to the hammer spring rod.  There is no way to swap in a set of reduced-power hammer springs.  I'll be MacGyver-ing mine, with a new factory replacement set on the way in case I completely screw the pooch.

[ppeeks21]

I realize that I never posted a follow-up as to what actually happened.

So, I made a jig for the hammer spring assembly that allowed me to securely grab the spring about 2/3 back from its forward end, and then compress it from that point in order to take all compression off the rear end of the spring.  Next, I used a 1/4 inch diamond pin on my Dremel to carefully remove a tiny portion of the rear and now free end of the spring.  It seemed to help a little.  So, I took more off.  It helped again, a little bit.  And then I screwed the pooch.  Not knowing the relaxed free length of spring was a problem, because my next cut took off just enough of the spring so that when fully extended, it did not reach fully from rear end cap to front shoulder of the guide rod.  And THAT resulted in a complete let-off of force BEFORE the hammer hit the firing pin.  The result: light primer strikes, FTF.  Oh well, at least I had another pair of spring assemblies.  I decided that not knowing the free length of the spring in its uncompressed state was too big a hurdle to overcome, so I've just used the gun a lot since then and the springs have definitely relaxed some, and more each time out.  So it was a fun but frustrating learning experience.  CZ should ABSOLUTELY make and sell a properly sized, reduced power hammer spring assembly for us SASS cowboys.

[ppeeks21]

Revisiting this old post of mine.  Since then, I learned how to easily remove the hammer springs one at a time, relieve the spring force on the end cap with a vice, a pair of clamps, and a strip of wood with an appropriately sized hole drilled in it. AND I replaced the OEM hammer springs and the sear springs with lighter replacement springs made for this gun by Shotgun Boogie (his spring kit also includes a lighter lever spring with a new detent, but I had already successfully found and installed a lighter lever spring).  AND VICTORY IS MINE!! The gun now operates as it really should right out of the box, if CZ-USA is listening (hint hint).  The gun breaks open from gravity and a slight flick of the wrist alone when the lever is pushed over -- and by that I mean I can open the gun with only my right hand.  And there is no snap-back, so the breech remains 100% accessible for shucking empties and loading another pair of shells.  ATTENTION CZ-USA IF YOU ARE LISTENING: this gun is primarily bought for SASS Cowboy Action Shooting use -- the Shotgun Boogie spring set is what makes it actually suitable for that sport.