S&W 79G Trigger Work and Seals - How difficult?

[buellm2]

I guess I spoke to soon.   Just took the 79G out for a few shots.  After about 6 full power shots, I could hear gas leaking.   The leak was definitely not from the piercing assembly.   I could clearly hear it leaking from the breech area.   I started wondering if I should shoot it at all.   It really appeared to be unfired when I first got it.   The loading tray behind the breech was still perfectly finished and clean.   Now that I've fired it several times, I can see faint markings on the loading tray.

[78gCollector]

I guess I spoke to soon.   Just took the 79G out for a few shots.  After about 6 full power shots, I could hear gas leaking.   The leak was definitely not from the piercing assembly.   I could clearly hear it leaking from the breech area.   I started wondering if I should shoot it at all.   It really appeared to be unfired when I first got it.   The loading tray behind the breech was still perfectly finished and clean.   Now that I've fired it several times, I can see faint markings on the loading tray.

It sounds like gas is getting by the exhaust valve.  To answer a question you posed earlier, it's always best to replace the exhaust valve while the pistol is apart.  The seal on the brass valves deteriorate just like the others do, and it's the only seal to take a bit of a beating every time you pull the trigger.  You can replace it with one of the white hot valves out there, or send it in to JGAiruns for a rebuild. 

[buellm2]

What is a "white hot valve"?

[78gCollector]

What is a "white hot valve"?

They new manufacture valves made of plastic and some sellers call them HOT valves.  Based on some chrono testing I've done, they do give you an increase in muzzle velocity. A few of my pistols have them, but the rest use rebuilt ones from JGAirguns.

Here is a pic of a HOT valve from one of the guys who sells them on eBay as well as a couple of JG rebuilds.

[chuckinohio]

Paul

I have one of the Daisys the trigger is terrible so the gun is really terrible.  Inexperience with this Daisy model lead to the purchase.  My air pistol has the "D" stamped on it.  D for dumb enough to buy it.    I collect Hy-score, Accles & Shellvoke, and Healthways but no Daisys. 

An old friend gave me a 78G.  After finding out how enjoyable the 78G was to shoot I started buying them (78 & 79Gs) when price and condition met my standards.  Wonderful air pistols similiar to my Crosman MK1 & MK2.

Thank you for sharing your experience.

The Daisy pistols went through a series of changes from 1981 through 1984.  The earliest of them were made using Smith parts, and are identical other than the markings.  Throughout 1981 a series of small changes were made, but they were pretty close to 78/79gs.  In '82 Daisy started to incorporate more plastic parts, changing over the sight assembly, bolt, and power adjustment to all plastic designs.  The plastic bolt is no where near as smooth as the earlier metal ones!  Then, in the summer of 1982, Daisy began installing drop safe triggers in all of its 780s and 790s - and eventually the model 41.  Comparing an early 790 to a late 790 is like looking at two similar but very different pistols!

The addiction for me started with finding and resealing the 78g my dad bought back in '76.  That led to another and another, and so on.  I now have a pile of Smith and Daisy pistols!

Here are pics of a 78g and 79g in my collection that are only about 2k off in serial numbers.  The 78g has been modified with the drop safe trigger while the 79g is factory.  Daisy marked the bottom of the grip on pistols when the recall was performed, and after June 1982 all 780s and 790s came from the factory with the D on the handle and trigger installed.

  Is it safe to assume then, that any 78 or 79 serviced under the recall would bear the 'D' stamp on the base of the grip?
  Thanks for sharing your knowledge in this thread by the way, I love the minutiae of the hobby.

[buellm2]

What is a "white hot valve"?

They new manufacture valves made of plastic and some sellers call them HOT valves.  Based on some chrono testing I've done, they do give you an increase in muzzle velocity. A few of my pistols have them, but the rest use rebuilt ones from JGAirguns.

Here is a pic of a HOT valve from one of the guys who sells them on eBay as well as a couple of JG rebuilds.

I seem to recall reading that a crosman valve will work in the Smith if the pin is shortened.   The Crosman is a LOT cheaper.  https://www.ebay.com/itm/291838716343

[Swissairgun]

I bought a hot valve off the bay for my 79G and installed it when I replaced all the seals. Happy with it!

[78gCollector]

  Is it safe to assume then, that any 78 or 79 serviced under the recall would bear the 'D' stamp on the base of the grip?
  Thanks for sharing your knowledge in this thread by the way, I love the minutiae of the hobby.

If you love minutiae, I will soon have more available than anyone could ever want!  I've been working on a database of Smith and Daisy pistols for 2+ years now, and I've got 600 Smiths logged.  (I've also bought way too many of them along the way!)  By keeping track of serial numbers along with features of the pistols and packaging, I've learned a lot about them.  This has translated into about 15 typed pages of info which will eventually be turned into a website dedicated to the line.  I'm hoping to have time this winter to take a ton of pics that will complement the text. 

All Smith pistols and Daisy copies manufactured prior to June 1982 that were sent in had a D stamped into the grip.  Some are faint and others a bit messy when compared to the ones Daisy produced with factory drop safe triggers.  When I started the database I wasn't keeping track of the drop safe triggers because I wasn't really sure what to look for in pics.   I have kept track for about the last 400 pistols, and only 7 of them had the recall performed, so it's relatively rare to find one that has this "upgrade".  I currently own three of them, and rebuilt one in the 102k range that I posted pics of earlier in the thread.  Daisy actually did more to the pistols than swap out the trigger spring and  hammer for a two-piece design.  Based on the one I rebuilt, they also resealed the pistol with color coded seals, installed a new barrel with nylon valve connector, and replaced the hammer spring with a longer one.  The combination of new hammer and spring makes for a much different sound when the pistol is fired.  It sounds like not enough gas is getting to the pellet!

[buellm2]

Finally got around to resealing and reassembling my Smith and Wesson 79G.   The trigger originally was unbearably awful so I cut 2 and a half coils off the trigger spring and carefully polished the trigger and hammer.  It's a lot better now but is still not exactly wonderful.   I don't believe the primitive S&W 79G trigger can be ever be tweaked to be as nice as a decent target gun trigger.   

 I used  a Crosman 1322 valve stem ($4.88) instead of a S&W 79 valve stem ($30.00).   I had to cut the Crosman valve stem to the right length, took a few minutes with a dremel.    So now it's up and shooting, there's no extra parts laying around and it's  holding pressure after 2 days.   I'll see if it's still holding pressure in a couple more days and maybe I'll get around to a chrono test one of these years.   I'll be better able to judge the improved trigger after a few hundred shots.   

Here's a pic showing the old S&W valve stem (top) and the new delrin, Crosman valve stem  before cutting it down.

[buellm2]

  Is it safe to assume then, that any 78 or 79 serviced under the recall would bear the 'D' stamp on the base of the grip?
  Thanks for sharing your knowledge in this thread by the way, I love the minutiae of the hobby.

If you love minutiae, I will soon have more available than anyone could ever want!  I've been working on a database of Smith and Daisy pistols for 2+ years now, and I've got 600 Smiths logged.  (I've also bought way too many of them along the way!)  By keeping track of serial numbers along with features of the pistols and packaging, I've learned a lot about them.  This has translated into about 15 typed pages of info which will eventually be turned into a website dedicated to the line.  I'm hoping to have time this winter to take a ton of pics that will complement the text. 

All Smith pistols and Daisy copies manufactured prior to June 1982 that were sent in had a D stamped into the grip.  Some are faint and others a bit messy when compared to the ones Daisy produced with factory drop safe triggers.  When I started the database I wasn't keeping track of the drop safe triggers because I wasn't really sure what to look for in pics.   I have kept track for about the last 400 pistols, and only 7 of them had the recall performed, so it's relatively rare to find one that has this "upgrade".  I currently own three of them, and rebuilt one in the 102k range that I posted pics of earlier in the thread.  Daisy actually did more to the pistols than swap out the trigger spring and  hammer for a two-piece design.  Based on the one I rebuilt, they also resealed the pistol with color coded seals, installed a new barrel with nylon valve connector, and replaced the hammer spring with a longer one.  The combination of new hammer and spring makes for a much different sound when the pistol is fired.  It sounds like not enough gas is getting to the pellet!

If you are interested in adding my 78 and 79 G to your database, let me know and I'll send you the serial #s and any details you want.

[bantam5s]

Finally got around to resealing and reassembling my Smith and Wesson 79G.   The trigger originally was unbearably awful so I cut 2 and a half coils off the trigger spring and carefully polished the trigger and hammer.  It's a lot better now but is still not exactly wonderful.   I don't believe the primitive S&W 79G trigger can be ever be tweaked to be as nice as a decent target gun trigger.   

 I used  a Crosman 1322 valve stem ($4.88) instead of a S&W 79 valve stem ($30.00).   I had to cut the Crosman valve stem to the right length, took a few minutes with a dremel.    So now it's up and shooting, there's no extra parts laying around and it's  holding pressure after 2 days.   I'll see if it's still holding pressure in a couple more days and maybe I'll get around to a chrono test one of these years.   I'll be better able to judge the improved trigger after a few hundred shots.   

Here's a pic showing the old S&W valve stem (top) and the new delrin, Crosman valve stem  before cutting it down.

That's definitely an inexpensive fix, I believe I spent the $30 on the valve stem for mine.

One thing to think about,  maybe it depends on the O-Ring material but with my 79G after a few days with gas in it the O-Ring gets expanded to a point that the cap is hard to get out or put back in.
If I just wait a little while it'll go back to normal though.

[buellm2]

   I had the same same problem with a rubber seal expanding from CO2 in one of my guns.   It was amazing how much it expanded from the CO2.   The white polyurethane seals don't absorb CO2.

[78gCollector]

If you are interested in adding my 78 and 79 G to your database, let me know and I'll send you the serial #s and any details you want.

I'm always happy to add more pistols to the database!  The basic info I'm tracking is SN, boxed or not, and drop safe trigger mod (D on bottom of hand grip).  If you've got one that's at a transition point - for example switch from Q to G prefix in SN -  I may ask for more info.