Smith & Wesson Model-79G and Model-78G (.177 and .22 cal) CO2 pistol

Smith & Wesson 79G 

With thanks to Jake.

Smith & Wesson Model-79G 

Smith & Wesson Model-79G and Model-78G reseal 

With thanks to Paul. He says:

The Smith pistols are pretty easy to reseal, and there are some great videos on Youtube that demonstrate the process.  The most difficult part of the rebuild is getting the sleeve retaining screw (located under the barrel at the front of the pistol) out of the slide, and then removing the sleeve it holds in place.  This is required to separate the halves of the pistol.  Sometimes that screw comes right out, and other times it's pretty firmly in place.  Once the screw is removed, it can be difficult to get the sleeve out.  I use the plastic part of a green concrete anchor as shown in the attached picture to help with this process and it usually does the trick.  On pistols that have rust and corrosion this can be an impossible task.  Luckily, yours looks lie it's in nice shape.

The only special tool required can be made by applying a Dremel to a standard tipped bit.  This tool is used to disassemble the piercing cap to replace the small o-ring inside.

Adjustable triggers were only installed on pistols with SNs below about 44,000 and don't usually show up for sale unless you buy an early pistol for parts.  Replacing/modifying the trigger spring and cleaning up contact points may get you what you're looking for...

A small percentage of Smith pistols were sent in to Daisy under a 1983 trigger recall.  The new and improved trigger was modified to make it "drop safe" because the Smith pistols and their Daisy copies (780, 790) could fire a pellet if cocked and dropped in several very specific ways.  Under the recall, Daisy added a two-piece hammer with a disconnector and increased the trigger pull to about 2.5x the normal 3ish pounds on 78/79g

Ernie adds:

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:

Smith & Wesson Model-78G CO2 pistol (boxed) 

With thanks to Callum.