When I recently gave my TX200. 22 back to our clubs gunsmith (needed the safety replacing) he tested it out of due diligence and it's banging out 11.5 ft/lbs with Exacts, a pellet I don't personally use as a plinker.
My point being they can put out the power when they're running right.
***Proud Member of Castleton Air Rifle Club***
If it is a TL (he of FB fame) 22mm skirtless piston I have the same in my full length TX .177, and have found QYS to be the best
I tried all the different headsizes of JSB Exact, AA Diabolo, FTT, RWS, in the rifle as standard, when it had a TbT short stroke kit, and in its current state, and nothing even came close to the consistent FPS, grouping, and accuracy of the QYS Streamlined 8.48gr 4.50mm head
Mine is running around 10.5ft/lb, standard AA spring, no preload washers.... it did take three strip and rebuilds to get the stroke length correct but it is now almost recoilless, completely impervious to hold (although I still wouldn't clamp it in a rest like a PCP!), and single figure FPS variance
Give TL a call when you have enough time to absorb everything he will tell you.. the man likes to talk! My best guess with inconsistency like you describe would be breach seals, excessive amounts of grease/lube or a spring that it is out of shape, poorly dressed, or has been heated and squashed
TX200 .177 21mm TL | TX200HC .22 22mm TL | Prosport .22 22mm TL
HW40 | HW45 | Diana Mod5 | Webley Senior....... Because PCP is like kissing your sister (apparently)
Breech seal, piston seal or both.
Probably the easiest springer in the world to service.
I have just done a new to me .22 HC.
It was at 9ft lb.
Took out an extended nose piston seal thingy...no likey.
New , new breech o ring and kept the same spring in it, a bit of bumlube here and there.
11.5 and very consistent.
Just ordered a few more Britseals as spares as I have x4 TX and x2 Prosports.
"Democracy is two wolves and a lamb voting on what to have for lunch. Liberty is a well-armed lamb contesting the vote!" -- Benjamin Franklin
An update to this...
I've stripped the TX this morning. I've found two possible issues:
1. There was only one o-ring breech seal- isn't there supposed to be two fitted?
2. There's another o-ring which sits in a recess in front of the breech seals. It's wider so doesn't look the same. It looks chewed up/split.
I've added a link with images, arrow pointing to the chewed o-ring. Any advice appreciated.
https://ibb.co/album/5YbCFm
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