Sleeve.

[TonyL]

I have seen that many people make sleeves to lessen the twang from cut to size beer cans.
I would like to try something that's not homemade.
The dimensions I need are 22mm o/d x 21mm i/d x 170mm length. I have looked on the internet and the nearest I can find is carbon tubing but the thinnest wall is 1mm which brings the i/d down to 20mm.
I even went round the supermarket and B&Q with my vernier gauge measuring anything that looked anywhere near my requirements (I got some odd looks when measuring vitamin pill containers, mop handles etc).
Does anyone know of a manufacturer that makes tubing of this size or even if this is an avenue worth going down?

On a traditional (even home made) sleeve, the end that goes to the front of the piston has "teeth" that are bent over. This enables the spring / top hat to keep the sleeve in place.
If you're considering a tube, you'd need to bond it to the inside of the piston to keep it in place.

I'd say a complete waste of time.

I know where you're coming from, Gary.

Rob, not a waste of time, it's just that Gary used the wrong wording there with "tube". He means the little cylindrical containers like the vitamin C types of things with a closed end. I've sometimes played with this idea also and wondered if any of them might be the correct size for certain pistons, but never went as far as going round shops with the verniers.