FX Wildcat consistency problems

[bchannell]

Still trying to get my WC 22 w/slug liner to shoot anything consistently. Every string with slugs or pellets swings something like 40-60fps, usually more.
It seems to shoot slower the longer I wait between shots.
I've tried 80-90 bar reg up to 125-130bar with hammer from all the way in or all the way out.
It's hard to find the knee when the fps is jumping all over the place.

Here's what I've tried:
* new AMP second reg, no improvement
* new Huma extra hi press reg, no improvement
* switched between pellet and slug port, no improvement
* new barrel probe oring, no improvement
* new reg orings, no improvement
* many different pellets and slugs all the same horrible es/stdev.

Any thoughts

my next thoughts are:
* hammer strike consistency
* ???

 

[rdtricks]

I find working with slugs in my Wildcat MK3 quite the challenge. One day things seem to be headed in the direction wanted and then it doesn't. I shoot a .25 cal so are challenges will be a bit different while being similar. A couple of questions for you: 1) When was the last time you cleaned your barrel and how often is a patch run down the bore? 2) Are you working with slugs of a similar weight and size: .216 vs .217 vs .218? I have found that slugs undersized can shoot well but not great while finding something that matches the gun will always shoot the same - good or bad. Have you tried sizing your slugs rather than going with the manufacturers claims? Are you recording your velocities with each weight and size of slug; anything showing some consitancy of speed?

These little guns are a blast to tinker with and developing the patience to hold onto a reasonable tune is difficult, especially when the search is formost in mind. Another thing you might try is watching some YouTube videos on tuning a PCP. Here are three videos dealing specifically with the Wildcat you may find useful: 1)

2)

3)

. Ted, Ernest, and Phil have probably forgotten more than most of us know about tuning PCPs. Another YouTuber you might checkout is Steve over at AEAC. While not having a video specifically on tuning the Wildcat MK3, there are a number of videos dealing with tuning different PCPs and the steps/ techniques are very much the same. Good luck to you!

 

[bchannell]

First, you are so right, these are fun guns to tinker with.

Here's where I am now. I had not cleaned the barrel. this is a new to me gun and it occurred to me that could be an issue. BUT, I really didn't think that could make such a huge difference, so I didn't have much confidence in it. Well, I THINK, at least I'm hopeful, I was wrong. I cleaned it. Pretty dirty, but only took 7 or 8 patches to get it clean, give or take. Decided to start over and check EVERYTHING. I took the barrel apart and it's a pellet liner 1:24. Soooo, I lowered the 2nd reg to 85-90bar, cranked the hammer all the way down on the screw, then set it on 6. Whipped out a clip and fed it some 18.1gr FX pellets. The pin probe HATES pellets, and I got several jams from two different clips. BUT, the good news is 12 shots with a 16fps es, at just over 900 fps avg. I had to quit there and do some mowing, but I'm hoping that was part of the problem. I did get quite a bit of soft gunk out of the barrel, so maybe.
I ordered a pellet probe from UA and I might be on the right track. I'm guessing that at least some of the es is from me trying to gently get pellets to feed and doing minor damage to them from two different magazines.

 

[rdtricks]

It is truly amazing how quickly slugs will foul a barrel when compared to pellets. Must have a lot to do with the additional bearing surface. I'm finding that tuning is a lot more art than science and it does get better the more I work at it and the less I mess with it. Hopefully that makes sense. Ted of Teds HoldOver on YouTube has been one of the best teachers for me as I attempt to learn this tuning PCPs magic. There are any number of others that show the way. Just something about how Ted explains things reaches me. Ernes Rowe is another one but for me a lot more analytical.

 

[Trucker3573]

I’ve had inconsistency in that platform come down to probe alignment. In my experience that issue has caused errant low velocity shots. Not really velocities all over the place. It would show signs of consistency then spit a shot 30 fps slow. There are several YouTube videos on aligning the probe. It has to line up with the transfer port every time to get consistent speed.

 

[bchannell]

I forgot to mention, I did check the probe alignment and ir was perfect. Also the pin probe is a bit less picky about alignment as the whole of the pin is open.

 

[Chukar60]

I have been watching your threads with interest. I have a Maverick that started life as a 25 cal Compact and now lives as a 22 cal 600mm pellet shooter.
I shoot 25.39’s from it. I had a bit of a struggle with the transition from 25 to 22. I don’t know what barrel length you have, but with the 600mm the stock 22 hammer weight would not drive the 25.39‘s anywhere near 900 fps. I ended up putting the 25 cal hammer weight in and using the slug port.
I am not a fan of super heavy hammer weights. A lot of people who struggle with tuning have at some point installed a hammer weight that is too much for their application. If you doubt that just go to the search bar and enter FX tungsten hammer and start reading. The tales of woe are numerous. It was a fad and a dumb one unless you are trying to drive very heavy slugs at high velocity.
Some people like to start at the bottom and work the hammer and plenum pressure in conjunction with each other until they reach their desired velocity.
I prefer a simpler method and this is how I tune all of my FX guns.
First adjust your hammer spring to maximum. Never mind the factory max. Put your power wheel on 7 then back the IHS out until the gun wont cock. Then turn the IHS in a little at a time until it does cock. You are using every bit of hammer you have available.
Next, degas the gun and turn the second reg screw in until it barely touches bottom. Do not go any tighter or you may damage the reg. Now back the reg screw out 1.5 turns or so and air up the gun. Once the gun is aired up you will need to back the reg screw out until you are at 90 bar. Shoot a dozen shots and make sure the adjustments are settled in and note your speed. Increase the reg pressure 5 bar at a time repeating the 12 shots and noting speed. Continue this process until you are 5-7% over your target velocity. I shoot 25.39’s at around 920 fps. I have not found them anymore accurate at higher speeds. Right now you want to see if the gun is capable of being consistent. To end up at 920 I would adjust the reg until I was at 985’ish fps.
Once there back the power wheel to 6 and see of your get a velocity drop. If not go to 5 and so on until you get a noticeable drop in velocity. If you can get to with 20 fps or so with the power wheel do that then screw the IHS in until you are at your desired speed. Make sure you shoot 12 or so shots every time you adjust the hammer. Once you are at 920 you should see your ES and SD’s tighten up considerably. SD’s should be around 3-5 fps or better. You can fine tune with the IHS in 1/4, 1/8 or 1/16th turns on the IHS. You may not see much velocity difference but you may see groups tighten up or open up slightly with the fine tuning.
Two things will mess this method up. One is too much hammer weight. More is not always better it can be and does get over done quite a bit. The second is the bugaboo with the Maverick and WC platform. The dread cocking lever linkage connector. This is a whole nother topic and anyone who has a Maverick or WC has or will have to deal with it. From the factory they are prone to the grub screws working loose and losing the proper placement on the cocking rod. This will manifest itself in inconsistent velocities and drastic extreme spreads.
If you have an appropriate hammer spring installed and the tune does not resolve your problem the next place to look is the linkage connector. It will cause the probe to be out of alignment and will show the kind of inconsistent velocities you are experiencing.
Do the tune first. This method of tuning is the fastest I have found for getting the gun on the knee.
Best of luck to you.

 

[Trucker3573]

Have you tried the regular probe just to see if it is better ?

 

[bchannell]

Well, the saga continues.
Today I tried pellets again, and the extreme spreads went from a low of 16fps for 6 shots, to over 100fps for 15 shots, most were in the 35-50 fps for es???

I'm really losing this battle. I have the hammer screw all the way in, and running it on 5, 6&7. with velocity in the 845fps for setting 5, 880fps for 6 and 900 for 7. I know it's not tuned, but my Impact was very tolerant of being de-tuned. It would be way off tune and shoot a string with an es of 4fps.

When I get time, I'm going to pull the liner and put a different one in. I have another liner for my Crown, that I know shoots very good. The liner in there now, when clean and I push a pellet through it, it is tight at the breech, then very loose in the middle, then of course the choke is tight. My Crown liner seems very consistent until you hit the choke, obviously. We shall see.

Also, next up is to remove the hammer and clean and make sure it's dry and not hanging up on anything.

I ordered a regular pellet probe, so we'll see what that does.

I checked the probe alignment, but a pin probe would seem to be more forgiving in that there is no hole to line up, you simply are ok if it is in far enough to seal on the barrel's breech oring, correct?

I will try the tune, when and if I can get the strange spreads below say 50-60 fps. With the wild spreads I'm getting, there doesn't seem to be much use in trying to tune. I mean, I've had two Impacts, a M3 and an M2 (X), and I had three or four Dreamlines, still have one, and I have a Crown, they are easy as all get out to tune. Heck most of the time, they shoot a bad tune well. Go firgure?

I'm using the standard 11.4gr hammer. HOWEVER, the previous owner had a Huma power tune hammer etc in the gun. I'm wondering if it has the extra power srping in it and that is simply overpowering the whole thing. Still it seems at minimum that it would still shoot more consistent that I'm seeing. I measured the spring and it is 56mm long, 1.4mm wire, 9.87 od and 6.96 id.