Quote Originally Posted by ken69 View Post
Thanks Mick, any idea how many Mk’s there were of the standard Mercury and which ones had the pins
MK1 and MK2 definitely had pins, I have a MK3 cylinder with a cross bolt --- from this thread it appears that not all MK3s had a cross bolt.

This is no surprise as BSA have a history of building what are called transitional guns which use up parts from the previous MK.
As an example, I've had a very early MK2 Airsporter in for repair that had no scope grooves as the cylinder was from a MK1 Airsporter --- BSA just used up the left over MK1 cylinders on the early MK2s.




All the best Mick