Tuning FX Wildcat MKIII Tuning advice

[anaranjo25]

Please see attached shot string data. 

Pellet: JSB .25 match king 25.39

Regulator: Huma (modified spacer, places the vent hole and channel inline with the factory adjustment hole). This modification made the "power plenum" substantially larger in volume as the stock regulator took up most of the space in that area of the tube. The new MK3 compacts are a single-pressure tube design. 

At the moment, I have the regulator pressure set at 125-130 bar (the factory reg pressure gauge reads something like 140 bar but the drop off occurs at 125-130bar bottle pressure). I plan to get a finer reading gauge shortly.

I have the gun set up to shoot at 930 fps on the knee on power wheel setting #7. The gun's MAX speed for this pressure was 940 fps. The gun gets about 35-36 shots before falling off the reg, and I get a good bit more before the speeds fall below 900.

With the JSB .25 25.39, I am using power wheel #6 which gives me speeds of 900-910. On power wheel #5, my speeds are 870-880 which is ideal for this particular pellet out of my gun.

The issue I am finding is that at these lower power wheel settings (IE: less hammer spring tension), my consistency between shots is not nearly as good as my max power tune. My ES and SD open up more than I'd like on lower power settings while on the reg. Of course, as I fall off the reg, I observe increases in pressure (well below the knee for the settings given hammer spring tension and the reg pressure)

Advice needed:

I will be trying king heavies (33.94) soon and will settle on the pellet that is most accurate out to 50M. If I decide to dial in the 25.39s, would you lower the reg pressure and adjust for a peak speed on max power for that pellet OR go UP in pressure, observe the decrease in speed then dial in the hammer to compensate (while hitting the max power target FPS for that pellet)?

Alternatively, would you leave the gun alone and accept less consistency (and sometimes, a flier or two due to a swing in speed) at the lower power wheel settings?

View attachment ref.1626034801.pdf

 

[2L8]

Alex, You are on the right track. Out to 50M is where you want to see what groups this current tune produces at different PW settings. If accuracy is your primary concern, shoot 5 shot groups at PW 7,6,5,4...@ your current 125-130bar with both the 25.39 and the 33.94. Adjust HS or BAR as necessary with your most accurate pellet. Your most efficient setting might not give the tightest groups. Have fun. These suggestions are based on my WC MK3 .30 (143bar) w/Huma and spacer and DL Classic .25 (125bar) w/PP

Patrick

 

[tor47]

I would also shoot for groups, by trying lower speed than 930. Do not get to hang up about chronograph numbers, just look at the groupings at target. When you try lower wheel settings, the first 5 shots may not be as acurate, as the hammer spring might need to setle in at new setting. So if the first 5 shots may not look as good, do another 5, before trying next setting.

 

[ladwict]

Good to read you know quite well what you are talking about . Please be aware that you can only tune your rifle very good for 1 pellet or slug . When you want your Wildcat to be 100% ZEN with both pellet weights you can not achieve this by 1 tune in optima forma. What you can do is tune for the heavy pellet 100% and then by tuning your power wheel down achieve a 80% fine tune for the lower weight. The best air efficiency and optimum balance in all aspects of a tune can only be done with 1 dedicated pellet or slug in combination with your rifle. ( read YOUR rifle) .The idea of using the power wheel to be able to quickly change ammunition sort and weight is pure nonsense for me . The powerwheel is usefull from my perpectiv to check several speeds on the fly at a given reg/ spring combo getting into the best harmonics zone fast. 30% ( or different ) weight difference or shape difference in ammunition definately demands for a different reg/hammerspring tune hence buy 2 iwildcats or re-tune each time you want to switch ammunition.

your current tune for the kings is now approx 6% below the plafond (940 plafond and 870-880 shooting you said) . A bit much to my taste giving les consistency and more spread from the reg . I would tune no more 2-3% below plafond with the King heavies on powerwheel 7 achieving also that nice speed of 880 fps. Then see if you can achieve your desired 870-880 with lower number on power wheel with the Kings as well. Maybe if you just put the King heavies in with your current setting you are about in the right ballpark using setting 7. Just give it a try. Furthermore in order to shoot the heavies at nice speed ( especially in case you do not achieve desired speed with current tune and the King Heavies on setting 7).I would advise you to install a bigger plenum and dual hole transferport . Simple free ( cheap ) extra power for those heavy pellets in order to keep your reg settings in below 150 bar territory...

so in short ... set your power wheel on 7 with current reg setting. Then check plateau with KING heavies. then tune down a little ( 2-3% till rifle feels “quiet” and groups well) . See if you end up at desired speed . If not increase reg and do all over. ( or install dual transfer port and plenum as recommended by me) . If you have your setting in fine order with the Heavies you just check with the lighter ammo if you can find an acceptable grouping on a lower powerwheel number. BUT that tune will never be 100% ! 

my 2 cents....

 

[anaranjo25]

All, 

Thank you for the advice. I am still waiting on an order of king heavies to arrive and will give them a shot. If they shoot when optimally tuned, I'll stick with them and if they don't, I will retune the gun (go down in bar and etc) for the lighter pellet. So far, I've only shot the 25.39s and the hybrid slugs (even at max power, they sucked out of my gun when compared to pellets). They would group then fly, group then fly...oh well. I also noted minimal expansion on impact....the lead is very hard. 

NOTE:

For all who get a new MK3 Wildcat Compact, know that the latest rev does not have a separate power plenum. The main tube is one continuous piece. The .25 barrels are all equipped with a dual-port transfer port and on the reverse side, a hole. They are marked "P" and "S" (pellet and slug). Your factory orientation for the barrel will be "P" unless you flip it or a shop tunes for max fps (my assumption). By installing a Huma reg, you will gain volume in the tube section after the reg (and it's noticeable) in addition to consistency over the factory reg (although your results may differ) but beyond that, you will have to live with what you got. Huma does make a larger dual-port transfer port but after testing, no noticeable change in speed resulted over the factory port. 

 

[ladwict]

Also the 2 hole transferport sucks as turning the barrel around changes your barrel index hence point of impact and harmonics. You should not switch this P & S every time you change ammunition from Pellets to Slugs and vice versa. Also I believe the way of airflow is different between the HUMA and the now factory transferport with the dual port included. Effects of airflow is not always only visible in shear speed ... ( I have the HUMA installed) Furthermore it is clear about the tube of current WC MK3 but you should try the newst power plenum from “910 airguntuning and repais”. They now have a nice 2.5” PP developed for your rifle. Makes the difference with your attempt to shoot the King Heavies ! Your HUMA power plenum spacer adds approx 14cc to the original PP and I estimate this makes a total of about 35 cc for your gun. I would recommend for a .25 shooting around max 60 fpe ( your rifle) you would ideally want 20-30 cc more . ( your current PP content is nice for a .22) . In case you go for the 910 PP please watch the diameter of your moderator as you have a compact version. Some Donny’s and Huma’s do the job well here.

Your WC MK3 is equiped with a superior liner and should definately be capable shoot the slugs you tried very well. Try different speeds ( around minimal 940 fps area for nice expansion) and do some barrel indexing and you will see with a bit of fine tuning that they are great ! Don’t give up so easy ... You know what you are doing but I believe you have to bring it a bit further to have full effect of your knowledge. It is not the WC limiting you with the heavies and slugs ( till a certain weigjt of course) but your tuning capabilities and endurance ... when you do as I say you will find the “YESSSS” moment with all projectiles you want to shoot. But again...best is to buy a Wildcat for every particular projectile

May I ask what you use your WC for mostly ? (Hunting , plinking , target...)

 

[anaranjo25]

I’m using it for hunting. I received the heavies and they shot more consistently accurate out at 50 yards (1/2 or better) but I am speed limited or maxed out at 840 fps with a max speed of 852 (I’m kissing the knee on this tune) I get 34 shots on the regulator set at 130 bar. I still have room to play with pressure which I will do next. The MK3 power plenum from 910 will increase overall length which will not allow a moderator like a DonnyFL to fit. I am running a 25/30 Tanto (plus 1). I’ll update the post after playing with the reg. There is a hard limit to airflow and I intend to find it.

 

[markc_66]

Any

I’m using it for hunting. I received the heavies and they shot more consistently accurate out at 50 yards (1/2 or better) but I am speed limited or maxed out at 840 fps with a max speed of 852 (I’m kissing the knee on this tune) I get 34 shots on the regulator set at 130 bar. I still have room to play with pressure which I will do next. The MK3 power plenum from 910 will increase overall length which will not allow a moderator like a DonnyFL to fit. I am running a 25/30 Tanto (plus 1). I’ll update the post after playing with the reg. There is a hard limit to airflow and I intend to find it.

Any updates on your tuning? I’ve had my wc .25 compact for just over a year but haven’t tried tuning yet. I wanted to do the recommended break-in of the regulator, and I have accomplished that as I have probably shot three 350 tins of the 25.39 jsb pellets. Waay more than necessary ha. I did buy a more precise gauge for the regulator from UA but I haven’t install it yet either but now it is about to get warmer out so I will do all of this soon.

 

[Chukar60]

How long is your barrel?
Why so high of a bar reading? I shoot my 25 compact with 25.39’s in the high 880’s and am doing it with 106 bar. PW is set at 7 but the IHS is at 4.5 or 5mm, cannot remember which.
For some reason people like to wind the second reg up very high on the Mavericks and it is not needed and may be causing issues with your hammer if it is not heavy enough to over come the 140 bar efficiently.