I've just .been playing with my 2 TX 200 rifles. One running one of my pistons @ 188gms the other @ 190gms so little difference.

Both ports 3mm shorter than standard but standard diameter, one stroked to 78mm & the other @ 82mm.

Started with 34 coil 3mm wire spring in both. HW 25mm seal & both rifles chucking AA 4.51 field out roughly the same Vo...788fps & 795fps

Now I usually have the TX running at 780fps 82mm stroke, skimmed piston, head removed & HW/short stroke adapter fitted, Vortek seal port standard but 3mm shorter, well 2.4mm actually with lovely firing cycle.

My 2 the firing cycle is is terrible, very slammy, fast but slammy. So springs out, new 30 coil 3mm wire springs in, btw the springs all have the coil spacing the same so lth is pro rata. Brass top hats made to take both pistons to 206gms.

Rifles now shooting at around 720fps, out with the HW seals, in with a Walther seal in one rifle, Vo now mid 740fps, Vortek Vac25 seal in the other rifle Vo 790fps, Vortek Vac25 fitted to the other rifle Vo now mid 780's.

Both rifles firing cycles feel better, but they ain't good by any stretch.

My .20 HW77 is short stroked to 75mm, rotating piston weighing mid 170gms, this too imo has a poor firing cycle.

Now when I say poor firing cycle & slammy, the cycles over lightening quick, it,s mega fast but I just don't like that, it also gives me a headache if my face is against the stock, head off the stock it's alright & seems reasonable, so to me these rifle are not user friendly.


It's difficult to put in words as most of you know when your trying to describe a feeling, but certainly we are all different, we each may like something different.

Sometimes a compromise is needed, it's no good having a rifle with the cycle you want if you can't shoot it long term, can't follow through properly or most of all hit what your aiming at. If it works for you go with it!