On my 97 there's naff all in the way of slack. Any movement of the comp tube and the underlever moves. Think what happens in the firing cycle. Think what happens to the barrel seal in changing temps!
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My TX 200 is stock apart from the spring n piston, but the amount of slack at the catch must be about 1cm in 2 different axis (left/right/up & down). There's a little slack on the comp tube, but only a tad.
Thing is, you get an action clocked up and put some mild force into it... good grief they're made of jelly. I know by not putting the lever back in the right place the zero is off. So I then wonder how off is off and how much that piston moves the comp tube and how much is imparted into the lever and into the barrel.
What you could do is free float the barrel entirely. Then sheath the barrel from the breech block with tube that doesn't touch the barrel anywhere, that's strong enough to hold the lever in place but weak enough that it won't impart any force into the breech.
I even had the idea of bridging the loading port with rod. Both guns are so weak there. In the end I think we thought we'd just make up a new action tube out of much stronger stuff.
Really, the lever should be disengaged from the compression tube, but the compression tube locked forward.
The tx is better in this respect in that it's seals don't compromise the closing distance when the hardness of the seal changes. The 97 is better in the respect that air isn't trying to get down past the seals at all. If the comp tube was locked off precisely, the seal wouldn't have such an impact assuming a good seal and the 97 route would be better.