My Mercury Ratting Rig

[Big Andy]

You know what Mick..if I had to get rid of all my rifles the one I would keep would be my Mercury, it’s been fettled by Ray Neil with a buttoned piston and double O rings and shoots lovely. One of the best rifles BSA ever made in my humble opinion, also the one I hankered after as a lad but could never quite afford.

[crowbar]

It will never be a Beat all so will you be Crying with the big "O" ring, Free falling with a Petty parachute seal or
a little piece of leather that's well put together?

Sorry I will take the Valium in future.

[T 20]

You know what Mick..if I had to get rid of all my rifles the one I would keep would be my Mercury, it’s been fettled by Ray Neil with a buttoned piston and double O rings and shoots lovely. One of the best rifles BSA ever made in my humble opinion, also the one I hankered after as a lad but could never quite afford.

I wouldn't argue with you over that Andy, it sounds nice. --- besides which you're bigger than I am and only live up the road.

Unfortunately, as my Mercury is at present it wouldn't get into my top 20 of guns to keep --- it's just plain nastiness itself.

I've tried double O rings in the past after reading a John Bowkett article on tuning the HW77 in AirgunWorld --- I always stick to just the one O ring now as I didn't get on with two.



I was looking at my Merc again this afternoon thinking 70 grams may be a bit over optimistic to remove from the piston weight in order to get the Mercury piston down to 270 grams.
Then I realised I'd already made a piston using an Airsporter latch rod for my prewar BSA, so after a quick strip I had the piston out and on the scales. :-

image.jpeg




By no real coincidence the prewar BSA piston is very close in length to the Mercury. :-

image.jpeg



So I'll definitely be building a new piston for my Mercury when I get time.






All the best Mick

[Big Andy]

I wouldn't argue with you over that Andy, it sounds nice. --- besides which you're bigger than I am and only live up the road.

Unfortunately, as my Mercury is at present it wouldn't get into my top 20 of guns to keep --- it's just plain nastiness itself.

I've tried double O rings in the past after reading a John Bowkett article on tuning the HW77 in AirgunWorld --- I always stick to just the one O ring now as I didn't get on with two.



I was looking at my Merc again this afternoon thinking 70 grams may be a bit over optimistic to remove from the piston weight in order to get the Mercury piston down to 270 grams.
Then I realised I'd already made a piston using an Airsporter latch rod for my prewar BSA, so after a quick strip I had the piston out and on the scales. :-

image.jpeg




By no real coincidence the prewar BSA piston is very close in length to the Mercury. :-

image.jpeg



So I'll definitely be building a new piston for my Mercury when I get time.






All the best Mick

I may be bigger but you are cleverer

[T 20]

I may be bigger but you are cleverer

I doubt that Andy --- anyone trying to tune a gun with a crap trigger isn't that clever.





All the best Mick

[T 20]

I doubt that Andy --- anyone trying to tune a gun with a crap trigger isn't that clever.

And a crap cylinder and a crap 5.6mm barrel as well.

I really must put a wanted ad up for a 5.5mm Lightning or Supersport barrel before I finish machining.

[TonyL]

Any progress on this, El Maestro?

[T 20]

Any progress on this, El Maestro?

I'm still on the case, Tone.

image.jpg



The reason I haven't updated you is because of the simple fact that the Mercury Latchrod isn't long enough to reach the piston head so I'm having to machine the piston in three parts.
The top hat will have to be steel and form part of the piston head with the latchrod threaded into it in order to get the piston length I need.
The top hat section will have to be let into the piston from the front and welded in to keep everything nice and strong.

As I've just finished the latchrod my next job is to machine the piston head to length and bore through it at the spring ID then open up half the depth to a larger ID so that I can leave a step on it for the top hat to sit in.
The idea is that the step stops the top hat pulling through the front of the piston --- once this is all set to length I'll weld the top hat in.

This lot would all be easier to explain with pictures which is why I haven't posted for a day or two.




All the best Mick