Mercury S more strip observations

[Phil Russell]

The Mercury and Mercury Challenger strips have both been covered by Guy (ggggr) and myself in the Idiots Guide posts 37/38 and 122. In both of these the barrel block was left attached to the breech jaws as there was no need to split the action at this point. Today though, I did split the action at this point. The rifle was a Mercury S with an initial chrono of 430fps (AA Field) so in dire need of a service. Cosmetically it was excellent although the breech seal was crumbling out and the action was quite resonant on firing. Strip followed the norm as given in previous posts but this time I also split the action at the breech jaws; simply undoing the securing bolt and removing it. Having the cylinder separate from the barrel did make re-assembly of the rifle easier. The piston was removed as usual by removing the cocking arm 'cage' from the cylinder. Gee, the securing bolts were tight ... pozi 2 bolts and I admit I feared for them rounding off. Did BSA employ gorillas on the assembly line? New piston O ring fitted (BS112) and a piston sleeve from a beer can. I left the original steel spring guide even though is was quite loose in the spring; which I also left as it seemed quite reasonable. On reassembly I noted that when you split the breech block from the jaws the securing bolt also acts as a securing bolt for the lock up plunger. In order to re-assemble you must locate the breech block in the jaws and then depress the plunger a few mm in order to fit the through bolt. I did this by pushing the plunger against a wooden block while holding the split action and feeding the bolt through. I did not know the plunger did this and I suspect that it could catch someone out as my plunger stayed in place and I did not realise it needed a slight push to allow the bolt to be fitted.
The old breech seal was completely defunct ... crumbling as it came out. A new one was made from urethane tubing, 8mm id and 12mm od x 4mm. This tubing was an excellent fit ... it is interesting to note that this 8mm x 12mm size is very common to many rifles. A 1m length costs very little and it is easily cut to length to suit whatever rifle you want.
All back together again after a relube with moly CV grease and we are now running at 750 fps. Very pleased. I would expect the fps to rise a bit as the O ring settles in ... it was a bit tight to assemble into the cylinder.
What a great way to spend a couple of hours on Boxing day.
I will add a few notes to the Idiots Guide Mercury strips.
Cheers, Phil

[look no hands]

I also spent a short time in the shed today attempting to put a supposedly Welsh Willy Supersport tuning kit into my Supersport but unfortunately it's way too big for mine and the spring won't even go into the piston, anyway that will be sorted soon with the help of Tinners.

I've found the easiest way to get the barrel back on to any of the BSA break barrel range is to assemble the plunger/spring into the breech block with it in the right position for the bolt to go through and then push the breech/barrel into the cylinder jaws lined up as if it was in the closed position and then when it is in as far as you can get it, you will have a small gap were the plunger is up against the cross pin, all you have to do is then push the end of the barrel down firmly (making sure the cylinder is against the floor) and it will slot home, you can then push the breech bolt (or pin like on most models) in and you're then sorted, I used to struggle trying to push the plunger down against a bit of wood and get the pin in at the same time but trying to balance the whole cylinder/barrel set up wasn't easy.

Another little thing to look out for is to check to see if the bolt that holds the back block threaded cup to the trigger block (Chambers numbers B1313(nut/bolt) and N116(threaded cup)) is tight when you strip the rifle for inspection/service as it can come loose and will make the back block spin and not undo, this happened to me once on my Challenger and I had to cut the back block off and chisel the threaded cup round to get it out the cylinder and buy a new back block, you will need a very thin walled socket to do the bolt/nut up with.

Hope my way helps.

Pete

[look no hands]

I also strip any new Airsporter/Merc/Challenger I ever get and put a new buffer washer/piston head set up in as it doesn't matter how good it cocks and fires when you receive it, there is always something nasty lurking inside and for piece of mind it's worth doing as they are a right **** to get the piston out when it's all locked up because of those horrid cheesy buffer washers disintegrating

Pete

[Gamocfx]

This has come at a useful time as I have a Mercury that cocks smoothly, just had a new breech seal but still wont spit a pellet out. I am loathe to touch it as other than the idiots guide I have no idea what to do....maybe a trip down to GGGR with begging bowl is in order?

I have to ask what is a Mercury Challenger? I googled pics and they look the same as mine?

[look no hands]

This has come at a useful time as I have a Mercury that cocks smoothly, just had a new breech seal but still wont spit a pellet out. I am loathe to touch it as other than the idiots guide I have no idea what to do....maybe a trip down to GGGR with begging bowl is in order?

I have to ask what is a Mercury Challenger? I googled pics and they look the same as mine?

The Challenger was the very last of the Mercury's, they had the better deluxe beech stock, also a breech block bolt that was carried across from the mk3/4 Mercs and the Maxigrip scope rail.

Pete

[Gamocfx]

Thanks Pete, never heard of them but now I not only want one I simply need one! In .177

[look no hands]

Thanks Pete, never heard of them but now I not only want one I simply need one! In .177

Good luck with that one, they are hard to find in .22 let alone .177 (unless you rebarrel a .22, once you've found one)

Pete

[Gamocfx]

I have a gun rack standing empty...5 spaces and I hope to fill it this year. You may be right about .177 back in the day there seemed to be an aversion to this calibre! I have no idea where that came from because from what I have read .177 was pretty popular pre war?

[Roundshot]

I have a gun rack standing empty...5 spaces and I hope to fill it this year. You may be right about .177 back in the day there seemed to be an aversion to this calibre! I have no idea where that came from because from what I have read .177 was pretty popular pre war?

Historically, .177" in the Lincoln Jefferies / early BSA Air Rifle / Improved Model D era was the bell & paper target league calibre, hugely popular pre-Great War.

'Long guns' of the Mod D type in .22" were marketed as 'sporting pattern' pest control guns. They had longer compression strokes + higher power.

The conviction that .22" was the sporting or pest control calibre held sway into the era of the Airsporter & Mercury, by which time the bell & paper target leagues had declined. Also, .22" guns often made a bit more power.

[look no hands]

Historically, .177" in the Lincoln Jefferies / early BSA Air Rifle / Improved Model D era was the bell & paper target league calibre, hugely popular pre-Great War.

'Long guns' of the Mod D type in .22" were marketed as 'sporting pattern' pest control guns. They had longer compression strokes + higher power.

The conviction that .22" was the sporting or pest control calibre held sway into the era of the Airsporter & Mercury, by which time the bell & paper target leagues had declined. Also, .22" guns often made a bit more power.

I used to enjoy having a calibre argument with a gunsmith I used to go into, he'd always say that .22 was the only calibre you should use for hunting but I find .177 is just as good, especially out to longer distances.

Pete

[look no hands]

I have a gun rack standing empty...5 spaces and I hope to fill it this year. You may be right about .177 back in the day there seemed to be an aversion to this calibre! I have no idea where that came from because from what I have read .177 was pretty popular pre war?

I'd suggest you fill that rack with some decent BSA's, there are far too many HW collections already on this forum, the balance needs to be redressed

Pete

[Gamocfx]

A rack of BSA's does seem like a good idea. There are so many variations on the Airsporter one could fill it with them alone!

[look no hands]

A rack of BSA's does seem like a good idea. There are so many variations on the Airsporter one could fill it with them alone!

You'll going to need a bigger rack

Pete

[Roundshot]

I used to enjoy having a calibre argument with a gunsmith I used to go into, he'd always say that .22 was the only calibre you should use for hunting but I find .177 is just as good, especially out to longer distances.

Pete

I think many shooters nowadays agree with you. Very unusual for the time, my Dad (now 93) was a .177" advocate and brought me up on .177" guns for hunting. Started me off with Crosman 766 & Webley Vulcan. Progressed to Original 45 & HW80. All .177", all very effective rabbiters.

[Phil Russell]

I do enjoy these calibre debates.
Personally, I chose .177 when I started shooting airguns about 56 years ago for no other reason than .177 pellets were cheaper than .22.
I knew nowt about power levels, trajectories (other than pure basics that pellets dropped in flight) and did not hunt. So it was pure economics.
And, horror of horrors, we used to look in our pellet trap stuffed with paper / rags and get the undamaged pellets out to use again.
Cheers, Phil