GTA
All Springer/NP/PCP Air Gun Discussion General => European/Asian Air Gun Gates => UK Airgun Gate => Topic started by: Fred J on April 21, 2017, 02:44:31 PM
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This week I installed a 12 FPE Vortek tune kit in my TX200 (.177 Cal). The gun in stock form was shot about 15 to 16.5 FPE, which was a little too hot for consistent accuracy, and restricted me to shooting heavier pellets to keep the velocity below 900 fps.
At any rate, I installed the 12 FPE kit, along with the included piston seal (my OEM seal was cracked) and one spacer between the piston and the top hat. Very easy to install: However, I could only install one spacer, since the gun would not cock with 2 or 3 spacers. My target was to get somewhere between 11.5 and 13 FPE from my rifle. Here are the 10-shot chrony results from the two most accurate pellets (JSB 7.33gr and JSB 8.44gr) after about 150 shots on the new spring and piston:
JSB 7.33gr
Low:856.4 fps
High: 880.2 fps
Average: 870.0 fps
Extreme Spread: 23.8 fps
Stand Deviation: 8.31 fps
Av. Power: 12.3 fps
JSB 8.44gr
Low:808.4 fps
High: 820.6 fps
Average: 813.3 fps
Extreme Spread: 12.2 fps
Stand Deviation: 3.31 fps
Av. Power: 12.4 fps
I anticipate that the spread will decrease when the spring and piston seal are fully broken in after about 500 shots. I also anticipate that the velocity will drop a little, but I should remain in my 11.5 to 13 fpe power target.
What these chrony numbers don't show is the improved accuracy of the rifle (see attached target). I am consistently shooting dime size groups out to 35 yards and dime to nickel size groups out to 40 yards. No more 'BONK' sound during the shot cycle, just a pleasant, short 'snap' sound. No more drama in the sight picture: The recoil is greatly reduced and the target remains in the scope through the shot cycle. And the gun is real easy to cock at about 24 lbs: This old guy can shoot this all afternoon and not get tired.
If your TX200 is shooting too hot or harsh, you might want to give the Vortek 12 FPE tune kit a try.
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Those are good numbers Fred.
I had the motorhead put a 12fpe VORTEK kit in my HW35.
It is a short cocking type as you know.
840fps and just short of 12fpe with 7.33 JSB pellets.
Many of my friends (US and abroad) believe the TX200 platform was designed for 12fpe..
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Here's an update on my TX200 with a 12 FPE Vortek kit, after about 600 shots:
I have settled on JSB 7.87gr pellets. Here's the chrony numbers (n=10 shots):
Low: 855 fps
High: 862 fps
Ave: 857 fps
ES: 7 fps
Stnd Dev: 1.73 fps
FPE: 12.9
I know this is a bit more than 12 FPE with one spacer installed, but that's OK with me, since I am not shooting in the International class for FT. I'm just an old guy who shoots Hunter Field Target that does not limit me to 12 FPE. I installed the kit to smooth the rifle out.
I also shot AA 8.4gr and JSB 8.44gr. What is interesting to note is that the average velocity with the JSBs went up from 813 fps to 826 fps. I guess the seal must be wearing in and giving a better seal.
I know that last year some guy tried out the 12 fpe Vortek Kits in their TX200, and found that their velocity dropped quite a bit after the the spring settled in. Apparently Tom at Vortek has corrected this in the current batch of springs.
By the way, I shot some paper today in a 15 mph cross wind, and got nickel size groups at 30 yards and 1 inch or less at 40 yards with the JSB 7.87gr pellets. I suspect that I will get stellar groups when the wind dies down a bit.
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Nothing wrong with those numbers.
Try some 4.52mm 8.64 H&N FTT.
You might like them.
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Nice work Fred and good shooting!
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I tried H&N FTTs, but I get some crazy fliers every 5 shots or so. I know FTT work well in some other TX200s, but for some reason mine doesn't like them. Maybe they fit too tight in the breach...
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I am not as anal as some but before each match, I take a tool (you can use the old 1/4" stereo plugs) and smooth out the skirt of the pellets that will be used in the match.
These pellets have already been washed in a sonic bath bath for 12 minutes, rinsed in water just below the boiling point so they dry faster and allowed to dry in the sun.
They then go into a plastic bag with a few drops of liquid bicycle chain lube and that is spread onto the pellets to coat them.
I do not know if this makes any difference and I know that most world champions and national champions don't bother doing it.
But it makes me feel like I am doing something.
More important in my mind is my recent cataract surgery.
I now have 15/20 distant vision and my HFT scores have increased by 30% from last year.
Good luck with your TX.
Stay safe
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Thanks for the advice, Frank. I tried lubing the pellets with Lemon Pledge, but I didn't see any real improvement. I think I'll try your cleaning and lubing process to see if it helps.
I'm not sure what the tool looks like (1/4" stereo plugs). Could you post a picture?
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(http://i1356.photobucket.com/albums/q733/barnydaddy/5436354558a68d09038ace909eee6bb9_zpsy1uri5an.jpg)
You can also use it as a pellet seater for your break barrels...
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One more update on my TX200 12fpe Vortek tune.
When I installed the kit, I had heard on GTA that the 12 fpe kit would drop in power after the spring settled in, so I installed one spacer that came with the kit between the top hat and piston. This gave me 12.4 fpe with both JSB 7.33 and 8.44 gr pellets. I thought the spring would settle in at about 11.5 fpe over time...
Well, after about a couple of weeks and 500 pellets later, I noted that the power had increased to 12.9 fpe for both JSB 7.87 and 8.44gr. Then the next day I noted that the accuracy began to suffer (I shot my worst GTA 30 yard rested target in a year: 181/200). I chronied the 7.87 pellets, and found that they were moving at 865 fps with a standard deviation of 5.5 fps (13.1 fpe).
So I took the spacer out (thank goodness that the TX200 is easy to work on). With the spacer out, the rifle now shoots at 835 fps (12.2 fpe). The accuracy improved dramatically, and now I am shoot dime-size groups out to 40 yards. The rifle produced a much better GTA 30 yard rested target score of 192/200 (shot off buckets and sticks).
I do hope that the rifle doesn't increase in velocity again, since the whole point was improving accuracy, and not power. If it looses 0.2 - 0.5 fpe when the spring settles in, so much the better.
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I use the 12fpe Vortek Kit in my TX. It is butter. I started with a SHO kit but it was too hard to shoot well. I would have been just as well off leaving the rifle in stock from. The 12fpe Kit makes for a very shootable rifle and totally transforms it.