Tuning Actual vs. advertised power for FX Wildcat mkIII Compact .25

[markc_66]

I have the same gun, .25 compact. My screws came loose on the probe as well not too long after I received it. I could only guesstimate where the original location was by the indents from the screws. Is there a more specific way to adjust accurately? Out of the box my shots are all over the place. I have not adjusted anything. Here’s an example with pw on 7 and factory reg setting around 140 I think, the stock gauge really sucks because the markings on the scale. I have bought a better huma gauge for it, but have not installed it yet so I can get a more accurate, reg pressure reading. Do you have any advice for me to tighten up the strings? I am a bit of a newbie but I have watched a ton of tuning videos. Just haven’t tried it yet.
These are with 25,4 g jsb diablos.

Shot count: 13
Low: 745
Hi: 884
Avg: 850
Spread: 139
STD Dev: 35.7
745
844
868
849
844
856
872
868
868
872
884
819
858

 

[swopever]

Are you talking about the two grub screws on the cocking arm? But yes, they also control pellet probe depth. Putting them at the indents is usually a good way. Watch Ernest Rowe's video "FX Wildcat MKIII Reassembly - FX Masterclass" on youtube as he explains what to measure and adjust.

Once you have pellet probe returning to correct spot each time you can adjust hammer spring to tighten up your velocity STDEV.

BTW I'm the original poster of this thread. Two biggest problems I had were 1) those grub screws coming loose and 2) after installing Huma reg gauge realizing the FX gauge was reading 10 bar lower. See my earlier posts in this thread for other upgrades.

With reg set at true 150 bar (instead of 140 bar with FX gauge) I now shoot 56 FPE, with 0.37 inch groups at 50 yards. Although my accuracy is fine, the regulator consistency is not impressive, with about a 15 psi spread and STDEV around 8. Others show STDEV of 2 or 3, I've never come close to that.

good luck

 

[Quad82]

I have my .25 MKlll Sniper shooting 2+ mags with a H912, L888 AV 896. I am at 59 fpe now with 50 cent size groups at 100 and most shots touching at 50 yards. I had it tuned to 71 fpe using the JSB heavy’s. It still held fair groups. But shot count really suffered.
My set-up is : 33.5 NSA slugs, 250 bar fill, reg at 145, HS 3.7mm, PW7, heavy hammer and plenum extension. First mag runs 250 down to 180 bar and the second mag from 180 down to 145 and then falls off the reg for a couple extra shots.