Lesson #7 - Making That Hammer Spring Nut Stay Put
OK… I worked through the earlier problems. After checking that my barrel's transfer port was still correctly aligned (it wasn't and somehow had rotated a bit while doing #1 through #6 exercises,) I set off to try and tune this Huma enhanced Wildcat.
Unlike many other Wildcat owners have reported, my hammer spring nut was not difficult to break free of the Loctite thread glue. In fact, the Loctite applied at the FX factory was not even sufficient to keep the nut from turning with the slightest pressure from an allan key.
I had the Huma installed and set to 129 BAR. Trying to test various hammer nut positions over the chrony was very frustrating. With each shot that loosie-goosey hammer nut would turn a bit counter-clockwise. I'd have to move it back into position with every shot.
Well, I ordered one of those jam nuts that seemed like a good idea. It installed easily and did a fine job of keeping that hammer nut from moving. The problem was, each time I tried a different hammer nut setting, I had to remove that jam nut.
Unlike that stated by the maker of the jam nut, my March 2020 vintage Wildcat's hammer nut required a 4mm allan key, not a 5mm allan key (see photo.) This meant I could only insert the allan into the also 4mm jam nut opening so far before it might also engage the hammer nut.
The jam nut is very thin (I guess so it doesn't take up much space in the threaded chamber and limit the adjust-ability of the hammer nut.) Long story short… given the constant removal of the nut, the softness of the brass, my over tightening, and not being able to deeply insert the allan, I rounded the opening. I had to jam a screwdriver into the jam nut and thankfully was finally successful in removing it.
I called FX support about the hammer nut looseness and was told I could put a few drops of blue Loctite along the edge of the hammer nut once it was in final position (see photo.) So I painfully tuned the Wildcat, careful to reposition the hammer nut back to its testing position as it turned slightly after each shot.
After getting an acceptable tune, I then dropped blue Loctite around the edge of the properly positioned nut. This proved to keep the nut in position (500 shots with zero movement) and could be easily removed should I want to again move the hammer nut (which I have done several times.)
When I want to move the hammer nut I simply rotate it clockwise. Because the Loctite is not really touching the threads of the nut itself, the nut breaks free from the surface tension of the Loctite sitting on its face. A few back-and-forth rotations and the Loctite peels off the chamber threads and all is again loosie-goosey.
I guess this works so well because during firing the hammer nut will only back out (counterclockwise.) It will never rotate in against the spring tension. The blue Loctite forms kind of a "dam" and surface glue against the nut face and the chamber threads.
If you feel the need for a little more secure bond, just wiggle the hammer nut back-and-forth a little after dropping on the Loctite. This will spread a little of the blue Loctite to first nut thread or two without cementing all the threads in place.
OK… I worked through the earlier problems. After checking that my barrel's transfer port was still correctly aligned (it wasn't and somehow had rotated a bit while doing #1 through #6 exercises,) I set off to try and tune this Huma enhanced Wildcat.
Unlike many other Wildcat owners have reported, my hammer spring nut was not difficult to break free of the Loctite thread glue. In fact, the Loctite applied at the FX factory was not even sufficient to keep the nut from turning with the slightest pressure from an allan key.
I had the Huma installed and set to 129 BAR. Trying to test various hammer nut positions over the chrony was very frustrating. With each shot that loosie-goosey hammer nut would turn a bit counter-clockwise. I'd have to move it back into position with every shot.
Well, I ordered one of those jam nuts that seemed like a good idea. It installed easily and did a fine job of keeping that hammer nut from moving. The problem was, each time I tried a different hammer nut setting, I had to remove that jam nut.
Unlike that stated by the maker of the jam nut, my March 2020 vintage Wildcat's hammer nut required a 4mm allan key, not a 5mm allan key (see photo.) This meant I could only insert the allan into the also 4mm jam nut opening so far before it might also engage the hammer nut.
The jam nut is very thin (I guess so it doesn't take up much space in the threaded chamber and limit the adjust-ability of the hammer nut.) Long story short… given the constant removal of the nut, the softness of the brass, my over tightening, and not being able to deeply insert the allan, I rounded the opening. I had to jam a screwdriver into the jam nut and thankfully was finally successful in removing it.
I called FX support about the hammer nut looseness and was told I could put a few drops of blue Loctite along the edge of the hammer nut once it was in final position (see photo.) So I painfully tuned the Wildcat, careful to reposition the hammer nut back to its testing position as it turned slightly after each shot.
After getting an acceptable tune, I then dropped blue Loctite around the edge of the properly positioned nut. This proved to keep the nut in position (500 shots with zero movement) and could be easily removed should I want to again move the hammer nut (which I have done several times.)
When I want to move the hammer nut I simply rotate it clockwise. Because the Loctite is not really touching the threads of the nut itself, the nut breaks free from the surface tension of the Loctite sitting on its face. A few back-and-forth rotations and the Loctite peels off the chamber threads and all is again loosie-goosey.
I guess this works so well because during firing the hammer nut will only back out (counterclockwise.) It will never rotate in against the spring tension. The blue Loctite forms kind of a "dam" and surface glue against the nut face and the chamber threads.
If you feel the need for a little more secure bond, just wiggle the hammer nut back-and-forth a little after dropping on the Loctite. This will spread a little of the blue Loctite to first nut thread or two without cementing all the threads in place.
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