Other Slavia 622

[PBradshaw]

Looking for some advice please with an old Slavia 622 air rifle; as you'll know this is an ancient thing but has a few things going for it in my eyes. The main thing I want to do is introduce my grandson to the sport and the size of this is perfect so he can handle the gun without size induced awkwardness whilst learning safety etc. The problem is the shaft through the piston rotates in use so that the notch on the shaft, after a dozen or so shots, no longer engages with the primitive sear making cocking impossible. I say "primitive" as it can be stripped down to very basic components although this takes some time. I can't see any mechanism to stop the shaft rotating in the piston although surely there must be something I am missing, does it require something to act in that slot perhaps?. Spare parts in the UK are not available and indeed the seal seems to be riveted on anyway; any advice on how to stabilise the piston would be gratefully received.

 

[Airfuture]

Take off the seal, weld as much as you can, sand as much as you can, and if that weld gets in the way of the spring at the bottom, make a custom washer and insert it into the piston.

 

[marflow 777]

the seal cannot be taken off there are no seals to replace, there are no pistons no parts whatsoever for the old Slavias
the cocking arm rest in the piston slot and that should keep any rotation to a minimum
there was a post in the last 2 weeks on a 618 about the seal and never read a solution
so you wrote the shaft was rotating in the cylinder but you meant to say the piston and, in the case, welding would be the fix

these old rifles are getting to the point that if you cannot make the parts or adapt parts that will become wall hangers

 

[Shuggoth]

A top hat in the piston would help, but you would need to get one made or find one of the right dimensions.

 

[Bear-of-Grayling]

I don’t see anything wrong with the piston. Sounds like the spring is binding. Probably from very rough ends. Polish the spring ends. The lever that goes into the receiver/piston slot may have to much slop/play In it. Check this. You may need to open up the fork end to a better fit. Start small. I would not put a weld on the piston. That is not the issue. Unless the sear shaft is spinning/rotating slightly in the piston. I have worked on these Slavia’s for a couple decades. These guns properly kept will last for many more generations.

 

[PBradshaw]

the seal cannot be taken off there are no seals to replace, there are no pistons no parts whatsoever for the old Slavias
the cocking arm rest in the piston slot and that should keep any rotation to a minimum
there was a post in the last 2 weeks on a 618 about the seal and never read a solution
so you wrote the shaft was rotating in the cylinder but you meant to say the piston and, in the case, welding would be the fix

these old rifles are getting to the point that if you cannot make the parts or adapt parts that will become wall hangers

You're correct, my error, it's the shaft that's rotating within the piston - just to be clear, is your advice to weld the shaft to the piston? Quite happy and able to do this although I'd be interested to know how the shaft was secured in place as per design?

 

[PBradshaw]

I don’t see anything wrong with the piston. Sounds like the spring is binding. Probably from very rough ends. Polish the spring ends. The lever that goes into the receiver/piston slot may have to much slop/play In it. Check this. You may need to open up the fork end to a better fit. Start small. I would not put a weld on the piston. That is not the issue. Unless the sear shaft is spinning/rotating slightly in the piston. I have worked on these Slavia’s for a couple decades. These guns properly kept will last for many more generations.

I wasn't perhaps as clear as I might have been; the issue is that the shaft, passing through the piston, is what's rotating so that the notch wanders away from being able to click into the sear. I am interested in how to stop the shaft rotating and in particular how it was designed to be held in place. It does seem that the easiest and most logical fix is to put a weld between the shaft and piston but that's the last resort if I can't reproduce how it was done at manufacture. I do very much appreciate your responce, thank you.

 

[PBradshaw]

Take off the seal, weld as much as you can, sand as much as you can, and if that weld gets in the way of the spring at the bottom, make a custom washer and insert it into the piston.

Many thanks - the seal would be destroyed if removed as it's riveted in place and manufactured ones are apparently as rare as hen's teeth even if there was a reasonable way to secure a replacement in place.

 

[DonR]

From your photo it looks like the rod could be spinning within the piston head, or the head+rod could be rotating with respect to the piston body. If it's the former, one solution would be to drill a cross hole through piston and rod, then insert a press-fit pin to maintain orientation. If the latter, it would be necessary to install a 'top hat' spacer before drilling, to provide a flat surface for the spring to sit against.

Don R.

 

[beerthief]

could the rivet be lose and letting the rod spin ? or how is the rod affixed to the piston ?

 

[Bear-of-Grayling]

If you attempt to weld it, the seal would most likely be lost by the heat. If you could degrease the end with high pressure air and degreaser, you could use JBWeld. It may hold. Welding would be a last resort and I would have a backup seal. It’s a seal that can be made/found. I think shaft is just peened to the piston. With the seal removed it could be correctly repaired. Getting a new seal is step one.

 

[marflow 777]

there is a post that the stem broke off and he welded it on but will it solve the problem and save the seal i doubt it
you are in a no win situation
now would JB weld work, it is a something i use all the, it could
they make a 24 hour type that is as strong as i know part number 82655 again let me state this is the best epoxy i have found in a tube
build a jig to keep the stem dead nut straight
if you can spin the stem as you apply the epoxy coverage should be find
could it work yes will it work for long maybe

 

[Bear-of-Grayling]

These are great guns. I would repair it correctly.

 

[marflow 777]

but with the early Slavia rifle the 618-622 and i don't know how many other models there are , they had an early version and a later version and of course the later version is easy to fix, snap on a new seal and away you go but the early version had the seals manufacture in place
now it would also be easy if you could swap the piston out with a later version but there are NONE

the cold stone reality is if you have a early version and cannot fabricate a fix of some kind you now own a wall hanger
hell, some of us might have a lathe and a mill and material to do the work but 99.5% don't,
i have read all there is to read and there is no work around that i saw beside filling the piston top with hot glue and turning it down to the right ID of the tube
could a seal be made and split and epoxied back together an idea where and what material to use and how to shape seen like a problem for the majority of us
could i fix it if i had all the tools and time and material or would i just fail

the piston in reality needs to be taken apart and rebuilt so modern seals could be use
it is a cheap rifle when it was new and still today, is there a point of no return or does stubbornness rule the day

the piston has to be modernized and if you can't do for next to free well be my guest

 

[PBradshaw]

Thank you all that replied, each reply has been valuable. It seems I have an early example which has the seal riveted in place. What seems to constitute the rivit is the end of the notched shaft having passed through a metal baulk end in the piston. As such the shaft seems to be held in place by being pressed tightly through the baulked end and time and use has loosened it. Long way of saying I whacked the rivit a few times which tightened it a bit and then spot welded (inside the piston slot) the shaft to the baulked end. All working well now ; with luck my fix will work for a while or at least as long as needed to get my grandson started, again, thanks to all.

 

[marflow 777]

i was thinking last night what would a i do
the shaft could be given strength with a top of sort, one piece and steel
it would slip over the stem and be epoxied to the stem and base
now with this fix you would have taken the piston apart, you would be starting over
the top hat would have been epoxied the stem as well a 2 cross pins installed
the top of the piston would have been cleaned off a spacer would be made to make up the lost height and adjusted to the new seal
spacer material is aluminum it is drill for m4 screw that will be installed in the base of that top hat with counter sunk heads
also the spacer will be drilled and threaded for the seal post
you get the point the piston could be remade, lot of work and sourcing bits and pieces
the cost would be not an issue because the goal is to make the piston
logic, imagination, common sense, skill and a very good plan and one last thing a boat load of luck

now this just an idea no more no less there would need to be fine tuning and there might be problems you might have a better idea but that is fine

us tinkerers just tinker

good luck mike