Blown piston - best way forward

[Andrewd2667]

The no 3 piston has blown with what looks like piston ring split and damage, along with excessive carbon.

How much damage to barrel - before you have to re-bore?

looking at all the pistons is it a case of replacement for all?

[kevski]

Any bore damage will require a re-bore, there is no other fix!

[Bryanj]

Used to be common on 175/250 twins if pushed hard from cold