After 8000+ rounds I broke it. I was shooting pop bottles hung from tree limbs at 75 yards. All of a sudden it wouldn't cock. Nothing worked so I took it home, got out my Air Arms master rebuild kit. In less time than it took to make this post it was rebuilt and back shooting. The big reason I bought the TX200 over other rifles was how easy it was to rebuild. For the price of a rebuild kit I can keep the rifle going on my own.
When I took it apart the first thing I noticed was the new spring was much longer.
The next, I looked at was the spring guide rod. This was where the problem was. This is the new one, notice the top and how crisp, and sharp the lines are.
This picture is of the worn out guide rod. Notice all the metal missing at the top.
The wear on the guide rod was what was keeping the gun from cocking. I went ahead and replaced all the wear parts. The picture below is the seal and bearings.
It's all back together and shooting great. I am shocked at how easy it is to rebuild. There are a few other high end spring guns. But after watching the rebuild video's I know I made the right choice.