Quote Originally Posted by ggggr View Post
Watch out if someone has had the tap out and fitted a bb that has jammed or left it out and the little spring has jammed.
Yes, Guy, I've just had a look at the spare MK4 action I have as I couldn't remember if they had an indexing plate or not, and as you say, they do have a plate ball bearing and Spring on the righthand side of the gun.
I'd remove this lot and also check to see if there's a nail wedged in the tap (yes, I've seen this) before going any further.

And be careful trying to turn the tap lever as they snap off easily (I've seen that as well), I'd be inclined to soak in oil and then try drifting the tap out very gently with a brass drift from right to left.



All the best Mick