I am guilty of chasing white rabbits, I have "upgraded" my ImpactX to current production mk2...I think..
In typical Tarantino style ill share the end of the story first. I am now consistently shooting unsorted/uncleaned .217 JSB Knockouts at 975fps dime size groups at 50yards, with a new 700mm superior liner that needs braking in. At 75 yards it opens up to a quarter. I am happy.... Just minor tunes from here out... fingers crossed.
The gun I started with was a ImpactX .25 600mm stx. It has evolved into a FXpower plenum, mk2 gauge, FX580cc bottle, 700mm superior, DonFL sumo, Huma transfer port, Huma single shot, NSA probe, money pit... This "money pit" does not include the include the K&L "cosmetic" parts, extra mags or optics, I am just trying to focus on what it takes to shoot the knockouts. I really could have saved time and money just buying a new mk2 impact, damn rabbit.
This upgrade started with the PP and 700mm then turned into a domino effect of problem solving. With a 700mm STX pellet A, I started the tuning and ran the .216 .217 KO at various speeds. The .217 grouped better across the board. The groups seemed to get tighter as the speed increased (all testing done at 50yards). I wish I documented this process better, sorry I don't have actual numbers. At this point I am grumbling at my Power Plenum because it is now set at 145bar offering me zero air savings, so after reading a ton about transfer ports here I thought I'd give it a shot. I didn't want to modify my only .22 TP so I ordered the Huma Set (probe and TP). The Huma TP style has dual elongated ports with a "slug catcher" between them. The process of removing the factory TP and installing the Huma for me involved a blow torch ac the factory TP was loaded with black loctite. If i remember correctly I gained about 10fps, and more mag issues. The Huma probe would catch the magazine as it traveled rearward and it would tilt the KO slugs when feeding. So I ordered the NSA adjustable pin probe. This did nothing for my Mag issues, it had a tendency to turn the slugs sideways in my mag. I was unable to find the K&L single shot loader that i loved in .25 for the .22, out of production maybe even discontinued. I settled with the Huma single shot hinge style.
So if this is the end of the road in my journey to shoot JsbKo well out of my impactx, I ended up with a few extra parts, 700mm stx, 2 sideshotFX plastic mags, huma probe, and a set of gauges. When/if I switch back to pellets hopefully the only thing I would have to do is swap the NSA probe to the FX probe and ill be able to use the mags again. I am done chasing the white rabbit, I am done messing with this gun. My modifications have created a bench gun that has real potential for long range, but not something i want to bring hiking anymore. I have been thinking about buying a wildcat for that purpose, but with all the extra impact parts it feels like a waste. I hope my experience helps some of the new guys plan their upgrades, save some money, and dissolve some of the hype.
In typical Tarantino style ill share the end of the story first. I am now consistently shooting unsorted/uncleaned .217 JSB Knockouts at 975fps dime size groups at 50yards, with a new 700mm superior liner that needs braking in. At 75 yards it opens up to a quarter. I am happy.... Just minor tunes from here out... fingers crossed.
The gun I started with was a ImpactX .25 600mm stx. It has evolved into a FXpower plenum, mk2 gauge, FX580cc bottle, 700mm superior, DonFL sumo, Huma transfer port, Huma single shot, NSA probe, money pit... This "money pit" does not include the include the K&L "cosmetic" parts, extra mags or optics, I am just trying to focus on what it takes to shoot the knockouts. I really could have saved time and money just buying a new mk2 impact, damn rabbit.
This upgrade started with the PP and 700mm then turned into a domino effect of problem solving. With a 700mm STX pellet A, I started the tuning and ran the .216 .217 KO at various speeds. The .217 grouped better across the board. The groups seemed to get tighter as the speed increased (all testing done at 50yards). I wish I documented this process better, sorry I don't have actual numbers. At this point I am grumbling at my Power Plenum because it is now set at 145bar offering me zero air savings, so after reading a ton about transfer ports here I thought I'd give it a shot. I didn't want to modify my only .22 TP so I ordered the Huma Set (probe and TP). The Huma TP style has dual elongated ports with a "slug catcher" between them. The process of removing the factory TP and installing the Huma for me involved a blow torch ac the factory TP was loaded with black loctite. If i remember correctly I gained about 10fps, and more mag issues. The Huma probe would catch the magazine as it traveled rearward and it would tilt the KO slugs when feeding. So I ordered the NSA adjustable pin probe. This did nothing for my Mag issues, it had a tendency to turn the slugs sideways in my mag. I was unable to find the K&L single shot loader that i loved in .25 for the .22, out of production maybe even discontinued. I settled with the Huma single shot hinge style.
So if this is the end of the road in my journey to shoot JsbKo well out of my impactx, I ended up with a few extra parts, 700mm stx, 2 sideshotFX plastic mags, huma probe, and a set of gauges. When/if I switch back to pellets hopefully the only thing I would have to do is swap the NSA probe to the FX probe and ill be able to use the mags again. I am done chasing the white rabbit, I am done messing with this gun. My modifications have created a bench gun that has real potential for long range, but not something i want to bring hiking anymore. I have been thinking about buying a wildcat for that purpose, but with all the extra impact parts it feels like a waste. I hope my experience helps some of the new guys plan their upgrades, save some money, and dissolve some of the hype.