Show Us Your Wildcat Hammer Spring Adjuster Nut Mod

Forums PCP Airguns Show Us Your Wildcat Hammer Spring Adjuster Nut Mod

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    CHUCK
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    The FX Wildcats have a "hammer spring adjuster nut" that threads into the rear of the breech block, which is used to adjust the hammer spring tension. The problem with it is that it sits very loose in the breech block threads, and if thread lock is not used the shot vibration will cause it to back out over time. This causes the velocity to change from where it set and consequently the accuracy is affected. To prevent this nut from backing out from its initial setting FX uses something like Loctite to lock this nut in place. The only way to free it up to make adjustments is to use a heat gun or micro torch to heat up the nut until the thread lock fails.

    Many of us have struggled to find a way to hold this nut in place after adjusting it without having to add more thread lock to it, which necessitates heating it up all over again each time we want to make another adjustment. I personally have tried PTFE pipe thread tape…not good. I tried various grades of thread lock…no good. I tried Vibra-tite…better but not great. At one point I even came up with the hair brained idea of flattening the threads with a small hammer so as to impart some resistance and hold it tight…that was a real bad idea that almost ruined the threads in the breech block. Since then I gave up and have just been using Medium Strength Loctite to hold the nut in place after adjusting it, and then torching it to get it loose whenever I need to adjust it again…a real pain in the ass! This is one of the things that makes me wonder why the engineers at FX couldn't come up with a better idea.

    Well I came up with a new idea that actually works, and does no harm to the threads in the breech block. Nor does it require the use of thread lock or torches! I recently had to fix one of the tank adapters that I use to fill my guns with. As part of its pressure release it uses these little tiny Delrin balls…so I had to order some of these to fix my adapter and have on hand for spares. I got to wondering what would happen if I drilled a couple holes in the hammer spring adjustment nut and put a couple of these Delrin balls in the holes, to put tension on the nut and hopefully hold it in place. I made the hole slightly smaller than the Delrin ball so that I had to press the ball into the hole with a pair of pliers. Here is some pictures showing what I did…and it works! 

    So lets have some FUN! Please show us what your solution to this problem is!

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    SeeOhTwo
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    Hello Chuck,

    I just got tired of messing with the whole thing and came up with this. Once adjusted for the .25 caliber 33.95 grain JSB, I never touch it, but it's nice to know I can. Great idea with the Delrin balls! Good luck Bro!

     

    https://www.airgunnation.com/topic/fx-25-wildcat-hammer-spring-adjuster/

     

    Glenn in Texas

     

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    n2stuff
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    My WC MKII didn't even have lock-tite. Mine also looks very different than yours. I use blue lock-tite and it does move after a while. I think the version 1 that had a jamb screw kinda like what you are showing to stop the hammer spring slide thingy from backing out. My biggest problem now I'm shooting 22 cal with 24g slugs and I have run out threads screwing it in to get get the max velocity. With 21g slugs I never ran out of threads before the FPS started going down. Does anyone know if Ernest Rowe makes a heavier hammer or spring? Also, your idea looks like it may stop the backout problem. I don't want to use RED lock-tite that's for sure. I have also read that galling the threads doesn't work and you could damage a lot of parts doing so. Please keep us posted how this works out.

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    Spikedog
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    Two great ideas Chuck and SeeOhTwo. I’ve had a mk1 Wildcat for two years now and the hammer spring adjuster would loosen just walking around with it. No factory locktite. Tried Teflon tape and it worked for a while. Recently installed a Huma and purchased the jam nut from FX. Initially when I tried to tighten the jam nut both would turn. I put a o ring between the two and got it to snug up on the adjuster and aligned the two hex heads so I could get the Allen key through both. Now I can adjust at will with no problems and it stays where I put it. Just my little mod.

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    JCD
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    Chuck, I think I like that better than mine but just to share a quick and dirty mod for those (like me) less willing to drill (I always mess something up).

    In the pic, the plastic screw you see is from an auto parts store. Use to hold trim panels on cars. Plastic screw inside a plastic sleeve that expands as the screw is turned in. The catch is that these are two long for use in the pictured location. The hammer will hit it if you don't trim it shorter. I cut it down with a simple snip of the scissors but than had to tape the sleeve that expands with electrical tape (couple wraps) so the screw held tension as you turned it in. the holes in the back of the action overlap so the HS adjuster nut peaks thru the opening this is in. If you use the right diameter panel fastener (an I don't recall what mine was) and place one side of the expanding sleeve to face that gap the HS nut peaks through, it picks up some tension as the panel screw expands. Mines held for close to a year now. I've wanted to do a cleaner version since first attempt but don't want to mess with success

     

     

     

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    CHUCK
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    Wow JCD that is one heck of an idea you had there! I am thinking I should rename this topic to something like: "Show me you Wildcat Hammer Spring Adjuster Modification!" I am guessing there have to be lots of other guys that came up with ideas on how to hold this darn thing in place. 

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    JCD
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    Chuck, I didn't mean to take anything away from your post, sorry if I did. 

    On my 'mod' – I have a parts bin full of these panel fasteners so it was a supper simple attempt for me. My first attempts usually don't work so well 😄. I'll replace with a cleaner one some day soon. Especially since I have 2 others that need the same treatment. The one in the Pic is a .177 (yes I was lucky enough to find an FX ST barrel that actually shoots .177 VERY well at 18-19 fpe, the other 4 attempts were mediocre at best) but I also have a .22 and .25 WC with wandering nuts.

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    CHUCK
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    Oh no JCD please don't be sorry! I like your idea and am fascinated wondering what other thought of to solve this pesky problem. So in all good humor I renamed this topic to encourage everyone else to tell us what they did to solve this problem. And I even added a final line to my original post that says, "So lets have some FUN! Please show us what your solution to this problem is!" You gave me the idea to present this topic the way I should have in the first place, which should have been "here is what I did, now show me what you did!" I bet there are lots of guys who tried everything under the Sun to solve this dilemma. From one Wildcat lover to another… I have an Original Wildcat .25 with SmoothTwist barrel, and my new Wildcat .30. It would be just too cool to have a .177 and a .22 also! :) I can imagine trying to run that by Karen!

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    JCD
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    Well, since I have to run and no one else has jumped in in this, I'll just add this…

    I think a longer 'bolt' and a drilled/threaded hole from the left side, with a Delrin tipped grub screw (mutant/veteran style) as well as rear access to the HS nut without removing the stock…… solves this problem. FROM THE FACTORY.  Of course then I'd have to buy new guns which would be a problem right now so I'll stick with superficial…. I can drill the stock but I won't drill and thread the action.

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    CHUCK
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    Got to love these Wildcats though …… especially if you love to Tinker with things

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    JoeKool
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    Had a local machine shop make me a few from brass.  Turn with a flat head screwdriver. Made two years ago.  Use them in my Wildcat MKII and Streamline.  Works great!

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    airgunfans
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    I will trying applying some Nyogel damping grease to the thread. They come in different degree of viscosity.  

    https://www.nyelubricants.com/stuff/contentmgr/files/0/66c7054d886f9e9f6c678586b87750c5/en/lubenote_dampinggrease.pdf

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    CHUCK
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    Too Kool, but Joe what keeps them from backing out from vibration? And also is there any problem from them not having an inset for the spring to ride in?

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    JoeKool
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    CHUCK

    Too Kool, but Joe what keeps them from backing out from vibration? And also is there any problem from them not having an inset for the spring to ride in?

    Those are my spare blanks in the picture.  The machinists let me keep for possible spares later.  The final ones are in my rifles, they are set and I don’t think I’ll remove them for a post.  Lol!  (my tunes are perfect, not doing all that again) But the final ones are the exact same specs as the OEM’s.  The inset for the spring is machined to specs as the original hammer spring tension nut, except they adjust with a slot designed for a flat head screwdriver and have more threads on purpose (not too many they where measured during fab and designing).  Two drops of blue loctite once adjusted and they don’t move from normal use.  But, with a flat screwdriver I can easily move them again and start over.  Just like the OEM ones but beefier but designed to actually make adjustments without stripping out.  (I’ll post pictures first chance I get)

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    West
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    Guys! 

    I have may wc mk2 coming and trying to find a fix before my hand on it. I just want to clarify,  does the wc 0.22 and 0.25 has the same thread dimension of 16×1?

    My trigger finger just ordered 2 pcs of 16×1 a moment ago and forgot to ask the question i am asking now!😂

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