TX200 - Mk2 piston into a Mk3?

[NickG]

if it's not the length of the guides it may well be the centralisation of the rod in the piston - is it centred correctly ? Also is the rear guide "brim" OD the full size of the main tube of the gun, thereby preventing it from moving off centre ? Also look at the trigger block - does the lead into the hole in the trigger block through which the piston rod passes show any signs of being hit / metal contact ?

Would have to be a mile out to prevent cocking

also check any "power washers"on the rear guide are of the correct diameter to go inside the bore of the piston .

[Shed tuner]

Would have to be a mile out to prevent cocking .

depends on the profile of the piston rod mushroom, but yeah, would have to be quite bad...

[NickG]

The end of the original mk2 rod is a different shape to the mk 3 , though the latch sears are identical , both profiles work fine in the mk 3 .

[Shed tuner]

The end of the original mk2 rod is a different shape to the mk 3 , though the latch sears are identical , both profiles work fine in the mk 3 .

yup, and WD and ISP are different profiles again... I have had this problem once, so not making it up... rod was way pi55ed in the piston; bore of guide was loose enough to allow it to not centralise, got kinda stuck on the way into the trigger housing. It;s not exactly likely, but seeing as we seem to have exhausted all the sensible causes...

[FPoole]

The end of the original mk2 rod is a different shape to the mk 3 , though the latch sears are identical , both profiles work fine in the mk 3 .

Was just looking at my spare pistons and found a MarkII stroke piston with the MarkIII profile. I think it came from a MarkII in the 13,000 range of serial numbers.