Pistons in the 280mm versus 288/312mm calipers

[Timbo 0]

Are the pistons in these calipers the same dimensions? I'm about to fit the latter, but the pistons are a bit past it really and I'm wondering if I can be a tight git and use the pistons out of my old calipers if they're in better condition and will fit the new calipers.

[Supercharged 2]

They might be I suppose - both 54mm but not sure if the length etc is different... Big Red sell new pistons

[Timbo 0]

Yup, BR235461 £21.90 each. Did I mention I was tight? :).