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Tuning Fx impact mkii .25 tuning help

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I had a problem tuning after installing the power plenum . And after the installation of the power slug kit with the more hammer and slower return spring it then began to make more sense, to me. The gun is shooting great and tuned @110bar shooting the new 34.9 nsa slugs @920fps on max and on min power @880fps in cold temperatures. I felt a little lost until I added the power kit. Hope that helps 


 
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Ok, so I put in the slug spring, and as I suspected, I had to turn it down to line 1, almost closing it off before I saw a reduction of speed. I was shooting 970 from wide open down past the first line, maybe a turn or two before closing it completely. I turned the hammer spring out a turn or so, and on max, there is no play in the preload. On min, the preload has a bunch of play. The extreme spread was reduced to about seven fps after I turned the hammer spring out. I'm now getting 970 on max with 25-grain kings and 930 with 26-grain hades on power level 2. It was nice to see chrony numbers with a standard deviation of about 2-3 with many hitting the same speed. I removed the slug spring, put the stock spring back in, and started at line 4 into a turn or so from line 2 before the speed drops below the consistent 970 fps. It looks like my hammer spring preload needed to be backed out about a turn or so to clean up the extreme spread. If hybrids end up shooting well out of this barrel, I'll be in good shape. I aimed for 950-980 with the hybrids and 26 & 29 grain lighter weight NSA slugs. I'm curious to do more testing once my 600mm superior heavy barrel is built and shoot the 33.5 & 34.9 grain. It seems like the slug spring might be for shooting heavier weight slugs with longer barrels to give more power during the dwell time, which I don't need at the moment.
 
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I had a problem tuning after installing the power plenum . And after the installation of the power slug kit with the more hammer and slower return spring it then began to make more sense, to me. The gun is shooting great and tuned @110bar shooting the new 34.9 nsa slugs @920fps on max and on min power @880fps in cold temperatures. I felt a little lost until I added the power kit. Hope that helps 

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I'm assuming that you have the 700mm barrel to get 920 at 110 bar with 34.9-grain slugs. Once I get my 600mm barrel going, I'll prob need to turn the reg down to 125 bar or so. Jeez, I better start an excel spreadsheet with all the tuning numbers and setup points so I can keep track of what's going on with each barrel.
 
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I do have the 700mm barrel with the slug liner A. The one thing is that on max I do have plenty of preload on the hst, that’s something that I have not had before. In the past I would be a half or even a quarter turn from max out on the wheel. But on min @875-880fps it’s very consistent, less than ten FPS. This is the most consistent tune I’ve ever had, however the temperatures have been between 18-34 degrees. I have found in the past as the temperatures rise so does my FPS, and my tune may have to change also hopefully not. Good luck 
 
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Im sorry if this has already been said jcote258, i usually get the same issue when setting the reg to high and not enough hammer spring tension. My beliefe is that if the hammer isnt hitting the valve hard enough to brake the stiction and it cant open consistantly. My experience is that 75 to 90% of max on the hammer spring works the best and find a reg pressure in that range to achieve your speed.
 
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Is there a max pressure not to exceeded when refilling . I have a scba tank I'm going to use to refill my FX Impact 3 . the tank is listed at 4000 psi is this ok
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The airgun has a max pressure printed on the side of it. I would stick within that pressure range as it could vary from the tanks max pressure range. I would also contact FX for your best answers.
 
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