Quote Originally Posted by cooper_dan View Post
I just happened to measure a standard one yesterday.

Active coils = 23
Active Length = 200mm (this doesn't include the collapsed coils at one end)
Coil OD = 20.7mm
Coil outer dia = 3.24mm
Coil inner dia = 14.22
Mean dia = 17.46mm

In my TX, 84mm stroke, 11 ft-lb in 0.177, gives 37% efficiency. Very good springs.
So as to avoid any confusion, can you confirm that the above spring measurements are for the Tx MK2? I will then add them to the database.

The current database entry reads:
Air Arms TX200 Mk1/2 21 (20.75)od 3.25 wire diam 207 / 220 length 23 active coils Source from Forum so very close to your posting.

Cheers, Phil

PS what is mean diameter? I can see it is id plus wire but I have not seen it quoted before.