I'm gonna agree that the Belsales Delrin bolt and pin is real purty
(works well too, took 8 milliseconds off the time it takes my bolt to open
)
As an alternative, there is the APB bolt from JAM enterprises (but they're in the states).
It's got a wierd springy section inside, so if a ball is half in half out of the breach, the back block still comes forward, but the bolt stays back - clever stuff and no more chops.