Short stroke drop in piston for the TX mk3?

[evert]

I know, I know, therese been a LOT of talk about shortstroking TX's the last years. So much, that I have problems finding and digesting all the info, so now I hope that some of you guys can help me out...

I have a .177" TXmk3, delivered to me in FAC configuration(no licence required here in Norway). I have done a fair bit of fiddling with the gun over the last years, different strokes and springs, but it doesnt seem to get as calm as I have been hoping for. My hope/wish is to make a new short stroke piston, and not need to alter the transferport from its original dimensions(TX parts are not that easy to get over here, so I'd like to keep the port unaltered). For sub 12fpe, as I wish to use the gun if I happen to end up shooting FT someday.

So, the the question is: what would be the optimum stroke, piston weight, sealtype, and spring for this "drop in conversion"?

[Shed tuner]

With std port, one of NickG's allly pistons will drop straight in and shoot nice at around 11ish FP

IIRC around 180g and 77mm stroke. I generally run a somewhat heavier piston with the same stroke, but with a reduced TP/ higher SCR.

[NickG]

Yes I run them at 11.2 They do make 12 dead easy though

[T 20]

The LGV piston drops straight in for a 76.2 stroke with a piston weight of 252g using a Weihrauch seal.

If you use a Vortec red seal instead of a Weighrauch seal the stroke gLes up to 78.2 mm.



All the best Mick

[evert]

Thanks to all of you!

Seems like you agree on the stoke at about 77mm, but 180 or 252 grams, thats quite a difference!

What kind of springs are you guys using?

The FAC spring that came with the gun seems a bit stiffer than the sub 12fpe springs I have seen in a prosport a guy I know came with.

I'm thinking to go with a softer thinner wire spring, something dimensionally close to the old meteor springs, does that sound sensible?

[Shed tuner]

Thanks to all of you!

Seems like you agree on the stoke at about 77mm, but 180 or 252 grams, thats quite a difference!

Depends on the port... for stock port I'd go lighter end (200-220g max)

[evert]

Yep, stock port. Thats what I meant with drop in, to keep the gun unaltered exept for a new piston.