Mercury S more strip observations

[look no hands]

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

Exactly what it was like for me, my Grandad had an old .177 Diana break barrel of some sort which I cut my teeth on and it's almost been like that ever since.

Pete

[TonyL]

Thread revival!

I finally got around to stripping my recently acquired Mercury S yesterday.

As Phil, the two screws holding the cocking linkage guide were ridiculously tight. Eventually one came out. The other remained more stubborn. As my 14 year old came into the kitchen, I had a "brain wave", asked him to tap the end of the screwdriver for me (acting as in impact driver) and out she came.

However, two bits remain.........it's years since I worked on Mercuries.....an early one and then a Challenger........

What do you chaps use to hold the "locking nut" for the breech bolt? Mine's turning with the bolt. Had a rummage through and I don't have anything that fits. Looks like I'll have to get hold of a 10mm slotted screwdriver and file a 6mm "step" in the centre.

And the back block is very stubborn. It's refusing to budge despite repeated whacks with the rubber mallet (hitting on the fat part near the hole at the front). Does one just keep trying? Would application of WD40/GT85 help? Would heating it help? So far, I've only tried with the action laying on my knees. I guess securing in a protected vice would help to get the thread started.

With the cocking link removed, I realise the piston will remove (once that end block is off!), but I prefer to also remove the barrel so that I can clean out the detent channel, polish the detent, relube and apply moly grease to the breech jaws / pivot.

[Phil Russell]

Well, I think you have got the option of a step in a broad driver blade correct. Good luck.
For the stuck end block, it reminds me of a Haenel VIE I got with a stuck block. It took ages to release it. In the end, after many attempts at whacking a bar while the action was clamped in a large vice, padded with rubber of course, I set the action barrel uppermost with the block completely immersed in a jar of various solvents (mostly releasing fluid but with a few contaminants there for various reasons) for maybe 24 hours. Back into the rubber and the vice and I, with baited breath, gave it a great clout with a rubber mallet. It went off with a great 'crack' but moved maybe 1/8 of a turn or so. Repeated whacks while moving the block back and forth finally got it moving. to unscrew. Phew.
Good luck.
Cheers, Phil

[look no hands]

Yes Tone you'll need a broad bladed screw driver and cut/file a small slot in the middle to go over the end of the bolt.

As for the end block you can try WD40 and so how that goes but I'd say you'll need a padded vice to hold it better, if you still can't turn it, then I was told by my engineer friend the other day, when I tried to strip his Airsporter the end block wouldn't shift, so I asked him to get it off, he said that he soaked it WD40 and then put it in his padded vice upright and put a bar through the hole in the block and put pressure on it from side to side (as if you where trying to do it up and then undo it again) and it apparently help free it up, not sure how many times you'll need to do it and you may need to do it over a period of time and then try giving it a whack with the rubber mallet or a lump of wood rested on the side of the block and struck with a hammer, go careful though because I've loosened the nut that holds the thread cup onto the block and it would just spin and not come off, I had to cut it off in the end and chisel the thread cup out the cylinder.

Hope that helps mate

[TonyL]

Cheers chaps.

Tuesdays can sometimes present a little play time, but too many commitments tomorrow, so I think I'll struggle to find the time.

Re the "nut tool", I managed to scrounge a couple of slot headed precision screwdrivers from work today. If I bind them together and that nut isn't too tight, these might just work. Will keep you posted.

On the barrel pivot subject, with the cocking slide removed there's far too much friction I feel anyway, so the tension would need backing off. Maybe overtight from new hence why the nut wants to turn with the pivot bolt?

[maximus]

You'll need that screwdriver for when you get yourself a Diana 280 and 34 too😁

[Shed tuner]

You'll need that screwdriver for when you get yourself a Diana 280 and 34 too😁

and a pro elite

[TonyL]

You'll need that screwdriver for when you get yourself a Diana 280 and 34 too��

I have a solution for that one, hopefully.

I managed to scrounge a couple of small screwdrivers from work on Monday. One is of the "precision screwdriver" type and one a sort of "Christmas cracker" type.

I had a tiny bit of time yesterday to see if they may work. The cheapie one was tapered and wouldn't fit in the small groove in the circumference of the nut. So I filed it down to size and parallel sides. The idea is that if I bind them together tightly they might just do the job if that nut isn't too tight. If it is, I might try and mount them in a little wooden block with holes drilled in to accommodate the 'driver shafts.

Then we'll have that mega tight end block to contend with.

And knowing my luck that piston buffer will also be mega swollen necessitating more welly!

I wouldn't be saying "never" to either of the Dianas.

[TonyL]

and a pro elite

Stop it!

[TonyL]

The action's at work now..

Those little screwdrivers into the locking nut didn't work. And that end block remains stubbornly whack resistant.

I couldn't believe my wife's benevolent offer on Tuesday night (as she hates guns, BIG TIME)...She was going to be nipping into a village on Wednesday where there's an airgunsmith. The 'smith and location will remain nameless as it would be unfair to name him.

She duly popped it in for me on Wedneday and he didn't want to work on it. He didn't have a suitably sized tool for the locking nut and said that under no circumstances did he want to remove the end block as he injured himself many years ago when removing one. Now, I don't want to seem cocky, but I stripped my early Merc when I was aged about 16 and it was fine, obviously observing safety precautions. The same applied when I later worked on my Challenger.

When she was there she put him on the phone and I asked if he wouldn't mind just starting the end block off and I'd remove it when I got home but he said he didn't want to try it in case it broke.

He also said to just use it as it is and enjoy. That, I'm sure, is a non-option, as there's a good chance the buffer will have turned to cheese (I have a new one ready) and I think there's a very strong chance that the mainspring is either broken or severely fatigued as the coils towards the end block look like they're very close together when you look through the cocking slot. The thought had semi-crossed my mind to put it back together and go and trade it in or even offer it on here as an on-going project, but I feel we have unfinished business and I'm sure it'll make a nice gun once I can get it apart......metalwork very good condition and just some minor marks on the stock. With some judicial polishing, a nice, soft spring and tight fitting guides it'll make a lovely, sweet shooting classic.

So, a colleague and I might be able to find a bit of time to nip down to the workshop at work where there should be suitable equipment. If not, he'll take it home one night as he has a well-equipped workshop there.

To be updated.......

[TonyL]

So my workmate, Dave, who has a workshop at home, took it home with him tonight. Got in around 5.30. Twenty minutes later he is ringing me to say "all done". In the space of twenty minutes he had ground an old pen knife down to fit the barrel axis nut, used his lad as an impact driver like I had done to get the cocking link bracket off, and got it loosened off. Clamped the cylinder up, got some wood around the flat near where the hole is on the end block and clamped a lever around the wood and got the end block started off for me by half a turn.

He's a good lad.

So I can bring it home with me on Monday and, hopefully, start the fettle proper on Tuesday.

[look no hands]

used his lad as an impact driver

I know you lot up north are supposed to be as hard as nails compared to us southern softies but using his lad as an impact driver is a bit harsh

Pete

[TonyL]

I know you lot up north are supposed to be as hard as nails compared to us southern softies but using his lad as an impact driver is a bit harsh

Pete

Kids can come in handy sometimes, Pete.

[TonyL]

So, I got the action home last night.

I'm ever so grateful to my work colleague for his help on this. And he did mention, the other night, that there was a mark on the breech jaws from the tool slipping that they were using to hold that locking nut. I've never used it before, but will try and dress the area slightly and use some cold blue touch up.

Now, I don't have a proper workshop space and most of my tinkering takes place in the kitchen. And that was a crammed mess last night as 'er indoors was "sorting" cupboards out.

But I was itching to at least get the barrel off, clean the area and pick out the dead breech seal. This happened. Strangely, the barrel detent didn't want to come out of its slot easily and took some persuasion. At first I thought maybe the detent spring had broken and kinked itself into the pivot hole in the breech block. No, eventually it came out. Spring intact. Nothing obvious. I've cleaned the slot out already and will give that and the detent a bit of a polish.

Now, I was going to remove the end block, piston and spring today. But I had the burning desire to get it done last night, mainly as to prove to the wife that it wasn't as dangerous a job as the 'smith said, as long as you take care. No problem; just as I did it years ago. Plenty of weight on the block and a tight, gloved grip and off she popped safely. No missing digits or other bits.

The spring is a snake-shaped mess!

Then I thought we'll find out how easily the piston will come out. Answer? It doesn't want to play! I have family, er, duties to undertake today but I've told her before we go out anywhere I need a hand holding the cylinder whilst I try and persuade the piston to come out for some fresh air. We'll see how we go.......

[TonyL]

Piston successfully removed this morning.

It certainly took a little persuasion!

As the piston head finally saw daylight, the crumbling mess of a buffer just flaked away. The 'O' ring was certainly tight, too.

Y'know, it's a fair few years since I have worked on a Mercury and a few observations came flooding back.....In my view, the build and finish on the piston is very poor. A rolled sheet welded up. Nowhere near as nice as that of many contemporary rifles. And the one on my Supersport that I stripped last year and even on the Gamo Vipermax was far better made and finished. Poor show, BSA, especially on what would have been, at the time, pretty much a flagship springer.

With the piston out, there I was guessing that the pin holding the piston head on might also need some persuasion. Nothing of the sort! As soon as the parallel punch made the lightest of contacts under finger pressure, out she came. I'd already bought a new buffer, pin and both Mercury and Meteor 'O' rings. The alloy piston head has a few scrawks on it that I'll polish out. Guessing that once the new buffer is in place and a little tension, the new pin should be a tighter fit? I'd cringe thinking that the pin could come out and contact the cylinder.

Once the piston was out and the head removed I had to call an end to today's proceedings. Just the de-burring and polishing and prep to do now. And removing the gunky mess made by the buffer from the piston, piston head and cylinder.

I had been toying with using a TX spring and getting some guides made, but I'm sort of thinking that I might try one of Will's kits in this? Good idea, Pete?

Oh yes, by the way, on the barrel pivot, the drawing on the Chambers parts site shows four washers. This one only had three. Do they need all four? Do others have less, like this one? Critical or not? Could it be that with one washer less than ideal that that is why the locking nut was so tight?