The TX200 is accurate as any skilled shooter can bring to this rifle.
It will put pellet's through the exact same hole as the last pellet shot at 40 yards, with the correct pellets and weather conditions and the rifle and scope set up and mounted correctly with Good Quality mounts.... like sports-match.
The tx200 can and has done half inch groups at 50, yards. again with the correct pellets, weather and skill.
The tx200 will hold its own against most pcp's, with a good skilled shooter behind the stock and trigger.
Find the best pellet for your tx200's barrel... I highly suggest you use/try Air Arms express pellets they are light weight and are pinpoint accurate at extreme long ranges.
all my Air Arms spring rifles 3,tx200s and 2 prosports love Air Arms express pellets and JSB exact express with unreal accuracy superb. theses come in one only head size of 4,52.
Make sure you have your scope mounted properly and not canted cross-hairs, and using good Quality mounts like Sports-match, cheap, nasty mounts give bad accuracy big problems and wast of time, money.
After your totally sure your rifle and scope are set up correctly, and in good working order, with decent scope mounts, and the rifle barrel is cleaned and leaded back up with using a pellet that you barrel likes then if you miss it is down to you to practice your skill,
Watch out for wind, wind plays tricks on us air-gunners by pushing the pellet off target making you think there is a problem with the rifle and scope. remember you will have to re- adjust you scope most times you go out shooting as of charges in wind. ( don't always blame your rifle or scope it could be wind or shooter that is the problem)
If the rifle shot well last time you used it, it is most likely wind..... (stop eating beans.... joke)
Many times at the club range I have seen a new shooter with a nice tx200 with a canted scope mounted incorrect with cheap mounts and using cheap crap pellets.
I have solved the youngsters problems in less than 15, mins by lending him some good scope mounts, mounting the scope properly and giving the lad some pellets that work.
and tips on how to hold and use a spring rifle..... the lad was amazed by the accuracy he was getting from the TX200.
Remember this England, the land of wind and rain.....

it is up to us to learn the skill to adjust and apply what is needed to judge for wind correction, so, to be able to hit the target. after all, is this not what shooting is about leaning the skill for adjusting for wind, pellet/bullet drop, trigger control, breathing.