S&W 79g Rebuild

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Riggers01

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I'm currently replacing the seals and piston on a S&W 79g pistol, but beyond a drop of pellgun oil on the seals what lubricant is best to use on the other moving parts? I'm thinking in particular, the front spacer sleeve which was stuck fast and a devil to get out.

I have some copper grease I use on revolver percussion nipples to great effect, but I'm not 100% about using it on an air pistol.
 
a little white grease nothing special
the front spacer sleeve, the first time you get to that point you are dead in the water
i use an easy out to hook into the tube and pull out
in your case the gun will be back together for another 15 years
Pellgun oil would be what i would use and i hope you were able to fined urethane Oring for the most part
you will enjoy the pistol if only they made them like that today, i have 2-78G and 1-79G
 
Thanks very much for your suggestions folks. I've run into another snag however. As I was putting the pistol back together I realized, there was no gas transfer port on top of the valve!

Any ideas on if/how to get around that?
 

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it is called a barrel valve connector it would be metal of some sort
so, a Crosman 2240 could use just a piece of urethane tubing
the CP2 uses two Oring with a metal TP
the S&W has just the piece and they fit in the holes, barrel and valve
picture of very dirty one at JG
if i remember right the connector only goes one way but it has been years
i am building to new chaser pistols so i have a TP here
OD 9.91mm , 7.42mm with nipples thick, body is 4.44mm with out nipples and our TP's 3.5mm
Orings are 6 x 2mm
tubing would be my first choice not rubber and on the hard side
SW11215ValveConnector.webp
 
Fantastic, thanks very much for such a detailed response! I'll give it a go and see how I get on.
 
the S&W uses a early transfer of CO2 no soft material
Crosman came along and made a better way to seal with soft material but for those who know that can be a PITA to get installed
Snowpeak came along and made the Crosman system brain death easy to install with 2 Oring and a connecting PT
if 2 Oring would stack in there and you could Epoxy them together your problem is solve
material could be just BUNA at 90 dura because the material would not be in contact with the CO2 at all times so absorption would be nothing

i wish i had one that was open to do some more thinking on it but you will solve it
 
Thanks for another really helpful response! I had been thinking about trying to stack o-rings, or getting a very short piece of brass tubing and shrouding it with o-rings or rubber tube.

As you say, the pistol is simply too well made and lovely for me not to find a solution and get it shooting again.
 
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