I ordered the parts last night from Tony. He was super helpful in answering all of my questions, and has already shipped the parts I can't wait to give them a shot. Of course, there is that small issue that I don't yet own a TX200. I hope to get one soon. In the meantime, another member has offered to let me shoot the holy grail of TX200/22mm conversions, and I hope to take him up on that! That should let me know what perfection feels like, and will give me something to work towards as I tune my rifle.
Yes, Tony reduces TP length on his conversions. He machines them down by 3mm. This increases velocity by 40fps with the same swept volume on JSB Express 7.9.
Quote from: Nitrocrushr on February 23, 2018, 05:04:09 AMYes, Tony reduces TP length on his conversions. He machines them down by 3mm. This increases velocity by 40fps with the same swept volume on JSB Express 7.9. By reducing the TP by 3mm does he not increase the stroke? Or does the new piston nose reduce the stroke by 6mm?-Y
Have any of you tested this kit at different temperatures and elevations? I'm just curious how much it is affected by these variables. It will be another month before I have a chance to check these things out, so I thought I'd throw the question out there...Thanks!
Quote from: Gear_Junkie on January 11, 2019, 12:27:50 PMHave any of you tested this kit at different temperatures and elevations? I'm just curious how much it is affected by these variables. It will be another month before I have a chance to check these things out, so I thought I'd throw the question out there...Thanks!Zack, I ran a test on my 22mm dual seal conversion today. Outdoor temperature was 27 degrees with a light breeze. I ran about 5 shots over the chronograph straight off the rack at room temperature, which was about 70 degrees. I then set the rifle outside on a sandbag in the fresh snow - 27 degrees for 1 hour.After sitting outside for an hour, I grabbed the rifle and quickly ran 5-6 shots over the chronograph straight from the outside. TX200 Rifle - .177 caliber - Tony Leach 22mm conversion kit (dual seal)Indoors - 70 degreesJSB 7.87Pellet weighed at 7.86 grains - 806 fps - 11.34 fpeOutdoors - 27 degrees for 1 hourJSB 7.87Pellet weighed at 7.88 grains - 816 fps - 11.65 fpe2.7% increase in energyNext, I swapped power plants and ran the exact same test using my standard sub-12 fpe tune with the Maccari Tesla MK2 sealTX200 Rifle - .177 caliber - with factory piston, JM Ultra XLD, Maccari Tesla MK2 main sealIndoors - 70 degreesJSB 7.87Pellet weighed at 7.90 grains - 810 fps - 11.51 fpeOutdoors - 27 degrees for 1 hourPellet weighed at 7.86 grains - 835 fps - 12.17 fpe5.5% increase in energyWhile the dual seal design helps to reduce the variation due to temperature changes, as with any springer there is still some variation. In a spring piston air rifle I think you will always see variation with temperature change.On the positive side, the amount of variation was 50% less than the hand fitted JM Tesla MK2 seal This summer I can do some comparisons in the summer heat.Steve
Quote from: Gear_Junkie on January 11, 2019, 12:27:50 PMHave any of you tested this kit at different temperatures and elevations? I'm just curious how much it is affected by these variables. It will be another month before I have a chance to check these things out, so I thought I'd throw the question out there...Thanks!Zack, I ran a test on my 22mm dual seal conversion today. Outdoor temperature was 27 degrees with a light breeze. I ran about 5 shots over the chronograph straight off the rack at room temperature, which was about 70 degrees. I then set the rifle outside on a sandbag in the fresh snow - 27 degrees for 1 hour.After the rifle sat outside for an hour, I quickly ran 5-6 shots over the chronograph straight from the outside. TX200 Rifle - .177 caliber - Tony Leach 22mm conversion kit (dual seal)Indoors - 70 degreesJSB 7.87Pellet weighed at 7.86 grains - 806 fps - 11.34 fpeOutdoors - 27 degrees for 1 hourJSB 7.87Pellet weighed at 7.88 grains - 816 fps - 11.65 fpe2.7% increase in energyNext, I swapped power plants and ran the exact same test using my standard sub-12 fpe tune with the Maccari Tesla MK2 sealTX200 Rifle - .177 caliber - with factory piston, JM Ultra XLD, Maccari Tesla MK2 main sealIndoors - 70 degreesJSB 7.87Pellet weighed at 7.90 grains - 810 fps - 11.51 fpeOutdoors - 27 degrees for 1 hourPellet weighed at 7.86 grains - 835 fps - 12.17 fpe5.5% increase in energyWhile the dual seal design helps to reduce the variation due to temperature changes, as with any springer there is still some variation. In a spring piston air rifle I think you will always see variation with temperature change.On the positive side, the amount of variation was 51% less than the hand fitted JM Tesla MK2 seal This summer I can do some comparisons in the summer heat.Steve
Quote from: Nitrocrushr on January 13, 2019, 04:48:27 PMQuote from: Gear_Junkie on January 11, 2019, 12:27:50 PMHave any of you tested this kit at different temperatures and elevations? I'm just curious how much it is affected by these variables. It will be another month before I have a chance to check these things out, so I thought I'd throw the question out there...Thanks!Zack, I ran a test on my 22mm dual seal conversion today. Outdoor temperature was 27 degrees with a light breeze. I ran about 5 shots over the chronograph straight off the rack at room temperature, which was about 70 degrees. I then set the rifle outside on a sandbag in the fresh snow - 27 degrees for 1 hour.After sitting outside for an hour, I grabbed the rifle and quickly ran 5-6 shots over the chronograph straight from the outside. TX200 Rifle - .177 caliber - Tony Leach 22mm conversion kit (dual seal)Indoors - 70 degreesJSB 7.87Pellet weighed at 7.86 grains - 806 fps - 11.34 fpeOutdoors - 27 degrees for 1 hourJSB 7.87Pellet weighed at 7.88 grains - 816 fps - 11.65 fpe2.7% increase in energyNext, I swapped power plants and ran the exact same test using my standard sub-12 fpe tune with the Maccari Tesla MK2 sealTX200 Rifle - .177 caliber - with factory piston, JM Ultra XLD, Maccari Tesla MK2 main sealIndoors - 70 degreesJSB 7.87Pellet weighed at 7.90 grains - 810 fps - 11.51 fpeOutdoors - 27 degrees for 1 hourPellet weighed at 7.86 grains - 835 fps - 12.17 fpe5.5% increase in energyWhile the dual seal design helps to reduce the variation due to temperature changes, as with any springer there is still some variation. In a spring piston air rifle I think you will always see variation with temperature change.On the positive side, the amount of variation was 50% less than the hand fitted JM Tesla MK2 seal This summer I can do some comparisons in the summer heat.SteveI was surprised to find that the higher velocity was shot in the lower temp rather than the higher temp. While 10fps is such a minor variation that it could have simply been due to "atmospheric conditions" like humidity, or maybe even pellet weight variations. Anywhoo......I do think that perhaps denser cooler air being compressed affects the velocity.
Great info, thanks for doing this test Steve!!! That's quite impressive that there is such a small difference in energy for such a large temp difference. Even with the Maccari kit, that's not as bad as what I thought it would be.Nice job Steve!
When I moved to North Carolina a decade ago I did a similar test using my .177 R9, oring sealed piston cap, and Krytox GPL205 lube. I left the R9 in my sunroom over night when the temp dropped to the 20s and shot a few CPLs over the chrony. A couple days later I left the gun indoors and chronied the gun in temps of mid 60s. I don't remember the exact velocity (I wasn't shooting sup 12fpe) but the velocity only varied 10fps between the two temps. I was surprised to find that the higher velocity was shot in the lower temp rather than the higher temp. While 10fps is such a minor variation that it could have simply been due to "atmospheric conditions" like humidity, or maybe even pellet weight variations. Anywhoo......I do think that perhaps denser cooler air being compressed affects the velocity.
Quote from: nced on January 13, 2019, 05:03:53 PMWhen I moved to North Carolina a decade ago I did a similar test using my .177 R9, oring sealed piston cap, and Krytox GPL205 lube. I left the R9 in my sunroom over night when the temp dropped to the 20s and shot a few CPLs over the chrony. A couple days later I left the gun indoors and chronied the gun in temps of mid 60s. I don't remember the exact velocity (I wasn't shooting sup 12fpe) but the velocity only varied 10fps between the two temps. I was surprised to find that the higher velocity was shot in the lower temp rather than the higher temp. While 10fps is such a minor variation that it could have simply been due to "atmospheric conditions" like humidity, or maybe even pellet weight variations. Anywhoo......I do think that perhaps denser cooler air being compressed affects the velocity.Its nothing to do with the lube, its to do with the expansion and contraction of the material used for the seal and the effect on friction it has, get your seal, measure it at 68f accurately for OD, then freeze it at 25f or so and measure it again, then heat it in an oven to 110f or more and measure it again...you will then see why the velocity goes up and down.lets talk in mm as thats what im used too.A seal at 25.4mm on the lip will shrink when cold, effectively sizing in better, it may shrink to 25.1mm, in an AA comp tube this is perfect sizing, the power will shoot up, smaller the seal will fail and the set up will go slammy.The same seal when hot will grow in size, friction will increase, efficiency will decrease and power will go down, this was seen by all competitors in Poland for the FT worlds this last year, it was well over 30C so guns were running 40C+ so well over 110fAt 68f or 20C the seal is within the normal working temperature and power will be what you have set when you built the gun, no one sets the gun up seriously cold or seriously hot i run a front seal on the 22mm set up with a lip around 22.1mm or just under, when cold it will fail, BUT the O ring takes over and the shot feel remains soft as the poly seal cushions the piston, when hot the lip diameter will grow to around 22.25mm and the seal will do all the work. The O ring runs zero crush, the groove is 18mm OD it sits in and the O ring is 2mm cross section so 22mm OD,it takes pressure to blow the O ring out to form a seal.We will never cure temperature shift, its akin so chasing your tail....you will only reduce the effects.
Love the idea of a double seal, one for hot weather and one for cold. Like of like DoubleMint gum! Could you achieve something similar with 2 o-rings? Different cross sections and different grove depths, maybe even different rubber compositions. Either really stupid or real great idea? -Y