Thanks gents (and Salopian
),
The current (28th) Machinerys Handbook gives five classes of clearances for shaft and hole; "loose running, free running, close running, sliding and locational." I'm taking it that when a tumbler moves on an action pin it should be either close running or more likely sliding.
Just for background, I'm setting myself a project to take a rattly coarse action, and then render it smooth and silky by adopting the best fits, smoothest mating surfaces, spring strengths and correct hardening.
If this means a bit of turning, reaming and polishing, great, thats just what I want to do.
Eug
