Canadian Airgun Forum

this had me thinking and I'm pretty sure from your explanation after you cock the rifle that its not engaging the sear, so either the sear or the rear of the piston sear engagement shaft is not lining up properly that is the only thing that makes any sense, it may look good but if its off it wont engage properly and there for wont cock and will slip back out

look here make sure your trigger peace is like the one in the picture and the sear and piston tube:
http://anotherairgunblog.blogspot.ca/20 ... art-1.html
also look here:
http://anotherairgunblog-sacramento-bee ... -jaws.html

_________________
"A candle loses nothing by lighting another candle"

I have a bad habit of not being clear. What I meant when I said the piston tail slipping past the sear was not the engagement when cocking, but when releasing it. If everything were working correctly it would obviously hold the piston, but my impression is when you cock it, and would normally assume the sear/trigger has the piston locked, it instead slips past the sear anyway and uncocks. So my understanding is you cock it, the sear is on top of the trigger like it's supposed to be, but somehow isn't holding. I also thought you meant that the piston and/or sear is moving away from the other to allow this to happen. Am I on the same page? If so then there is either too much wear or something is missing, like a washer or C-clip or whatever. And if so, is the piston tail moving up or to the side, or is the sear moving down or to the side, or both?
Unfortunately I still only have a 2D image of the sear to go on. I can picture what the rest should look like to make it work, but it would be nice to have the real image because I may be wrong. Like that one and only time in my life where I was wrong because I thought I was wrong but was not
So hook us up with some info and I or someone will get you fixed up. I'd fix it for you but I'm a wee bit far away in the far SW corner of the US... Which btw it was chilly after dark. So after running the AC till ~3pm, it cooled down to ~21C by 10pm and I had to put a flannel over my T-shirt. That's like the 5th time that has happened since summer! Feel sorry for me? It also rained for a day last week, we don't what to do with ourselves when that happens

Chevota,

There will be a pity party for you right after work-it'll just be me of course and in order to help me feel less bad about the weather where you are I should probably enjoy a cold beer and some salty snacks...which can't help but improve one's mood.
If you could return the favour by having a similar party for poor me who wants to shoot this super awesome Slavia 630 he has but can't cause the frick'en thing won't cock...well that would be swell.

I couldn't bear to work on the rifle last night and take pictures. Too frustrated.
I'll get some this evening and post them here for the hive mind of the Forum to reflect upon.

Thanks,

Aaron

Well for what it's worth some images and a video.

Pulled it apart again.
I think my initial thought that there wasn't enough pressure on the cocking arm was wrong.

Tried things without the spring in there and the piston engages the sear and the trigger but once reassembled same old, same old.

Images as requested, hopefully they are of value. Same with the video.

Part 2



Apologies, the movie is to large to be posted...

I'm thinkin maybe whatever holds the tail of the piston from moving upwards is worn. How's that part look?

All the contact points look good,
is it just my eyes or maybe just the way the picture came out but that third pic of the sear looks like its got a crack in it.

_________________
"A candle loses nothing by lighting another candle"

The parts I can see all look fine and built to last. So I have two ideas that might be the cause.
Pix 1 I doubt, but possible. Pix 2 is more likely. Can you tell me if when the piston slips by is the sear still up on the trigger, or does it slip off? Probably hard to tell but if you put your finger on the sear thru the slot you will be able to tell if it pushes on you finger or not. Pushing means it slipped off the trigger so the sears are not holding. If the sear does not push on your finger it means the piston tail moved up and over the catch.
Pix 2 & 3 are about the sears not holding and the fix.

Ok buddy had a chance to watch the video you send me, from what I can see and comparing it to my 630 everything looks to be working properly, so the only thing I can think of is what I was trying to explain before, your sear and the rear piston rod are not making proper holding contact and slipping out as you let off on the barrel. Remove the sear from the gun and line it up next the rod of the piston were it makes contact and snap a pic for us to see.

I think this is were your problem might be one of these two spots see pic.

_________________
"A candle loses nothing by lighting another candle"

Chevota and Ace,

We're narrowing things down for sure here.
I've just sent you both a second video where (for those who can't see the vid) I've pulled the rear "plug" that screws onto the end of the rifle out (contains the safety and sear). Into that I re-installed the trigger (with the little spring). Then I've "cocked" the rifle by engaging the end of the piston tube with the sear, safety pops...all good.
(Then when I pull on the piston tube, with a little pressure it pulls straight out; it's just not holding-*Wrong*)
I went back due to Ace's keen eye and tried again (I had been touching the trigger which in turn was just enough to release the sear).
This time the piston tube engages the sear and I can't pull it apart; huffing and puffing as well as wiggling is all to no avail.
What is going on when the spring is installed and everything is under pressure that I can't re-recreate?

Even though I can't re-create the issue, I'm partial to thinking that what Chevota highlighted in image #1 with the comment is the problem area:

"the shaft can move and/or flex in relation to the piston so without support at this point it will simply move up and over the catch."

It could be a combination of wear on the piston tube itself or the opening where it is inserting.

Here are some images that show wear in that area:





It could of course be wear on the sear and the trigger although I don't see anything obvious there; paint removed or corners rounded etc.

The other area that I thought it was odd that showed wear when I took it apart was the outside of the piston tube. I tried to describe this before but here is an image.



You can see the smoothing in the middle and the complete removal of the edge at the one end.

For the 6 million dollar question is this fixable with new parts and worth doing? Should I order a new everything and stick it in?
My fear is that I'd be throwing good money after bad to order the parts and by the time shipping is done... I might as well have just bought something else no?

Wear on the piston body is not an issue, and I doubt there is any wear on the piston tail shaft either.
That spot in the below pix is what I was talking about. Can you estimate how much wear has taken place? Maybe by putting the shaft in and wiggling it up and down? (That didn't sound right) I'd imagine a half to 1mm is enough to cause the problem. I'm guessing it's aluminum or zinc etc so if you cannot build it up weld you'll need to use a filler. Maybe epoxy a brass sheet to it. If steel then just build it up with weld if you can, but it doesn't look like steel to me.
Another option would to build up the catch on the sear with weld,which is steel. The sear is hardened so welding will affect that, but it should be fine. You can always heat treat it again if you're worried about it or if it causes problems later, but I doubt it will. Once all together you need to lube everything properly so this kinda stuff doesn't happen again. I'm big into lube (that didn't sound right either). How about I'm anti wear and friction... I use dry tungsten disulfide powder directly on high wear parts like that that, then a mix of that and grease for a wet lube over it.

Chevota,

You lost me at "weld."
That just isn't going to happen.
I went back in there again and played around without the spring installed. There is some play and although it seems minor, it is obviously enough to create an issue.
The damning thing is that everything connects and holds and doesn't slip and looks like it should work without the spring BUT once the spring is installed no dice. It must be loading the system or torquing it such that the sear/trigger/piston just no longer engage and hold.
I'm done.
I'm getting a new hobby.
My only hope is to find someone local with another 630 to swap parts with and isolate specifically what is the weak link...or take a flyer on ordering a new everything and hope that it restores right in the world....or throw it in the lake.

Thank-you all for your generosity of comments and time applied in troubleshooting. I'm sorry not to have arrived at the solution for the satisfaction of one and all.
Should that change I'll update the thread on the off chance it benefits someone else facing the same issue.

Over and out.

Aaron

pm'd

_________________
"A candle loses nothing by lighting another candle"

So you're not the kinda guy with a welder in the garage I guess.
How about JB weld (epoxy)? Just build that worn spot up with it, then sand or file it down just enough that the shaft fits. The epoxy is probably as good or maybe better than alum, and properly lubed it may outlast the original.
You could also build up the shaft instead with a sleeve. Maybe a brass tube that fits it, or by gluing some plastic to it. A little glue and plastic should be easy.... I can explain how if you want to try it.

Chevota,

I am embarrassingly that guy without a welder in the garage.
I hope we can still be friends.
I'll look into your suggestion of epoxy.
I banged around with a bit of aluminum from a can but was unsuccessful with the first attempts.
I haven't completely given up hope but will bang away as time allows.
Christmas is at our throats here and I (and suspect many here) will be busy with other things. I will not be able to apply the time and attention necessary.
Again, very much appreciate the time and suggestions.

Aaron