bsa mercury

[TonyL]

Nicely done, Steve.

Did you fit Mercury or Meteor 'O' rings? If the former, make sure you keep a watchful eye on the power potentially creeping up.

My .22 Supersport makes a lot more power with Hobby vs Superdome. If you have any to hand, it's a good idea to power check with the Hobby. I haven't power checked my Mercury S with anything other than Superdome as yet; but as it's safely under, all should be safe.

Also worth treating yourself to some H&N Excite Hammer from our good sponsor. Cheap as chips and excellent quality. Both my .22 BSAs love them.

Lightning- there have been a few threads and also, I think, an "Idiot's Guide" over in Collectables. You may have to "drop" the front sear to allow piston removal and I think it'll have the Maxigrip? You'll also need to obtain / make a dowel to clear the spring and exert pressure on the spring guide to facilitate spring removal and refitting. But not too hard at all.

But, yes, I saw it written many times years ago, but it does seem that the higher quality rifles, like Weihrauch and Air Arms, are easier to work on. And I'd generally agree with that. Fit and finish are better, too, and they're just so much better engineered and made. But, then, working on some of those lovely match rifles of yesteryear won't be so easy (especially the Giss Dianas), so I guess that dispels that!

Have fun and be sure to shout up if you need any help.

[Weasle]

Nicely done, Steve.

Did you fit Mercury or Meteor 'O' rings? If the former, make sure you keep a watchful eye on the power potentially creeping up.

My .22 Supersport makes a lot more power with Hobby vs Superdome. If you have any to hand, it's a good idea to power check with the Hobby. I haven't power checked my Mercury S with anything other than Superdome as yet; but as it's safely under, all should be safe.

Also worth treating yourself to some H&N Excite Hammer from our good sponsor. Cheap as chips and excellent quality. Both my .22 BSAs love them.

Lightning- there have been a few threads and also, I think, an "Idiot's Guide" over in Collectables. You may have to "drop" the front sear to allow piston removal and I think it'll have the Maxigrip? You'll also need to obtain / make a dowel to clear the spring and exert pressure on the spring guide to facilitate spring removal and refitting. But not too hard at all.

But, yes, I saw it written many times years ago, but it does seem that the higher quality rifles, like Weihrauch and Air Arms, are easier to work on. And I'd generally agree with that. Fit and finish are better, too, and they're just so much better engineered and made. But, then, working on some of those lovely match rifles of yesteryear won't be so easy (especially the Giss Dianas), so I guess that dispels that!

Have fun and be sure to shout up if you need any help.

Hi Tony.. I fitted Meteor O rings as suggested by some of our learned members. I was surprised at the way that the original Nylon(?) piston heads has swollen in size - maybe it was due to the plus gas I used to try and free everything up as the pistons were solid in cylinder when I first got the 2 Mercury's. The process of removing the pistons from the cylinder, with the swollen nylon heads and 'goo' from the disintegrated cushion washer was a 'job an a half'!!! The original heads also have a steel ring in them, however it was obvious that they were destined to be replaced with Aluminium items, procured from Mr Knibbs.

I was tempted to do away with the cushion washer below the head to increase the stroke, however that will be scoped in a later project.
I was shocked at the crudeness of the pressed steel pistons and again will replace these with some less agricultural items later. Does any one out there know of a direct replacement...maybe from a later Mercury?

The serial Nos of the guns are ZA 6156 & Z 4609 which I believe dates them as early '70's

Is the Lightning as crude internally?

The breach jaw/barrel fit on one of the guns was a 'touch slack' - 'Bar Door Accuracy' I'd imagine - however I managed to get them back to a very acceptable tolerance by alternately hitting each side on to a substantial piece of wood, using judicious force - as recommended to me by a well known and trusted gunsmith. Apparently using a vice to pull the jaws together generally leaves you with only one of the cheeks moving.

Anyway it was a pleasant(?) way of passing a Sunday.

Cheers Steve

[TonyL]

Hi Tony.. I fitted Meteor O rings as suggested by some of our learned members. I was surprised at the way that the original Nylon(?) piston heads has swollen in size - maybe it was due to the plus gas I used to try and free everything up as the pistons were solid in cylinder when I first got the 2 Mercury's. The process of removing the pistons from the cylinder, with the swollen nylon heads and 'goo' from the disintegrated cushion washer was a 'job an a half'!!! The original heads also have a steel ring in them, however it was obvious that they were destined to be replaced with Aluminium items, procured from Mr Knibbs.

I was tempted to do away with the cushion washer below the head to increase the stroke, however that will be scoped in a later project.
I was shocked at the crudeness of the pressed steel pistons and again will replace these with some less agricultural items later. Does any one out there know of a direct replacement...maybe from a later Mercury?

The serial Nos of the guns are ZA 6156 & Z 4609 which I believe dates them as early '70's

Is the Lightning as crude internally?

The breach jaw/barrel fit on one of the guns was a 'touch slack' - 'Bar Door Accuracy' I'd imagine - however I managed to get them back to a very acceptable tolerance by alternately hitting each side on to a substantial piece of wood, using judicious force - as recommended to me by a well known and trusted gunsmith. Apparently using a vice to pull the jaws together generally leaves you with only one of the cheeks moving.

Anyway it was a pleasant(?) way of passing a Sunday.

Cheers Steve

That 'S' of mine has the ally head but the buffer was severely swollen so I also had fun on stripdowm.. I can't remember exactly now about the piston, but do seem to recall it being nowhere near as nicely finished as my Supersport one. So I'd guess you'll find the Lightning a touch nicer inside. None of the weirdness with the mushy piston heads going on. If preload is sensible, removing the spring will be quite easy even without a compressor. If you do have a compressor, it'll be a good idea to use it if internal set up is unknown. With everything secure (and the "dowel" employed) it's much more straightforward than the Merc' with that harder to control end block.

My Mercury has a breech bolt as opposed to pin. Not as good as a proper set up, more of a halfway house, methinks. But the jaws weren't sloppy. My Supersport one wasn't, also, which was an unexpected bonus as it had patently endured a tough life. But I remember having to tighten the jaws up on a Mercury I owned years ago.

As you say, it's always good to have a tinker and bank that knowledge.

[TonyL]

Thinking about the internals a little more, especially in relation to the pistons, I can remember thinking back at the respective times and how disappointed I felt with the Mercury S. I did have an early Mercury back in my teens and also remember that not impressing at the time. With the Mercury S being the flagship break barrel for BSA at the time and attracting many fans even now, I expected better.

The Supersport, on the other hand, impressed with the quality of, and finish to, the piston.

[Weasle]

Are there any 'imperial ' .22 (5.6mm) pellets available ...of good quality?
I've got some modern Wasps....but they are not of the quality that we have become accused too.

Cheers Steve

[evert]

Here are examples of pellets that have worked well in my 5,6mm rifles (both BSA and Webley):
-RWS Hobby and Superdome
-larger head diameter H&N FTT
-Gamo Match
-Milbro Select

Not all guns like all the pellets, but one of these should probably work in your rifle.

[TonyL]

Although I have no personal experience of them, many used to talk very highly of the Defiants. But, maybe, hard or pretty impossible to get these days?

If it helps, that Mercury of mine does like RWS Superdome and the H&N Excite Hammer. Lots of other people have also stated excellent accuracy and compatibility with the 'Domes.

Now, that Supersport of mine......I'm not sure when the barrel diameters reduced, but this is an early Supersport (so 1986/7?). The Hobby snicks in very snugly and the rifle is very, very accurate with them. The Hobby is also the pellet that produces the most power in it, slightly shading the JSB Jumbo RS.

Hope this helps a little.

[johnbaz]

I was given an old mk6 action, the trigger block was missing, It had been unscrewed and the back block bush and cup were still attached!

I drilled two holes and stuck a screwdriver through the cocking slot in to the coils to pull a bit of weight off the spring then unscrewed it with a drill bit in the hole!!




Piston and mainspring were in very good nick!




Meant to say, I promised the piston and mainspring to a lad on facey, When I went to look for it I can't find it!, If I put it in the garage i'll probably never see it again!!

John

[Weasle]

Although I have no personal experience of them, many used to talk very highly of the Defiants. But, maybe, hard or pretty impossible to get these days?

If it helps, that Mercury of mine does like RWS Superdome and the H&N Excite Hammer. Lots of other people have also stated excellent accuracy and compatibility with the 'Domes.

Now, that Supersport of mine......I'm not sure when the barrel diameters reduced, but this is an early Supersport (so 1986/7?). The Hobby snicks in very snugly and the rifle is very, very accurate with them. The Hobby is also the pellet that produces the most power in it, slightly shading the JSB Jumbo RS.

Hope this helps a little.

Many thanks Tony
Both of the barrels are early....mks 1&2...and all of the usual are a bit slack. The modern Wasps produce the best power...by far!!!...however I've not been able to test the accuracy as yet.
I wish I could have been able to try these 2 beforehand...however they were seized solid.
It's been a great journey.
Cheers Steve

[Weasle]

Here are examples of pellets that have worked well in my 5,6mm rifles (both BSA and Webley):
-RWS Hobby and Superdome
-larger head diameter H&N FTT
-Gamo Match
-Milbro Select

Not all guns like all the pellets, but one of these should probably work in your rifle.

Many thanks....testing time is here again