Hot rodded Smith & Wesson 78g

[Pale_Rider]

 I was going to send it off to Timmy at Mac 1 Airguns to get worked on but decided to take a crack at it myself. Here’s everything I did to it:

1) Install upgraded poppet/valve stem

2) Swap stock valve spring for lighter one

3) Replace stock TP with 1/4” poly tube

4) Ported valve, barrel, and transfer to 11/64” (angled barrel and valve port for better flow)


Before the mods it was getting

488 FPS (7.6 fpe) with 14.3 JSB 


After the mods it’s getting

554 FPS (9.7 fpe) with JSB 14.3

540 FPS (10.3 fpe) with Hades 15.89



Shot string:

(1) 550

(2) 554

(3) 551

(4) 553

(5) 552

(6) 551

(7) 542

(8) 528

(9) 526

(10) 518

(11) 531

(12) 535

(13) 528

(14) 538

(15) 537

(16) 553

(17) 528

(18) 503

(19) 504

(20) 524

(21) 491

(22) 510

(23) 505

(24) 481

(25) 438


I was happy with the power I was getting and the consistency wasn’t too bad for a “high power” co2 pistol. What’s power without accuracy though. So I setup at 10 yards and was able to shoot three 5 shot groups before the sun went down. 

Best group out of the 3

 

[Roboslug]

Please tell us where you got that barrel. 

Do you find that the hammer spring adjustment has much of an effect on velocity/accuracy? 

 

[Pale_Rider]

The previous owner machined the barrel.

Turning the HST all the way only yields an extra 30 FPS. At this setting it wastes too much co2. The loss of shot count and efficiency aren’t worth the extra FPS. The way I have it setup right now the HS is backed out all the way, with the hammer a mm from touching the valve stem 

 

[biohazardman]

Nice looking gun and a good return on your power mods. I am waiting impatiently on a pair of forest green grips for mine. Have not yet decided if I will leave it stock or not. Such hard choices here in the first world we have.

 

[Pale_Rider]

Thanks Bio. Those forest green grips are going to look purdddy on the s&w. It was difficult for me to leave it stock. I’ve got a problem where I can’t leave certain guns alone. Not to the point where I’m trading too much shot count and consistency for power though. With the 78g I traded 40% of my shot count for a 30% gain in power. I don’t remember how consistent the stock 78g is but I don’t think I lost any consistency. Do you have any shot strings from yours?

 

[biohazardman]

I haven't even bothered to chrony mine as yet. Guess I will since I have nothing better to do. Tomorrow that is cuz it's late err early now.

 

[Roboslug]

Thanks Legionair. Mt only real mod is a Mac1 valve and a $20 red dot. At about 2-2.5 turns on the hammer screw I get about 70 shots per Co2 cartridge. 

 

[Pale_Rider]

Thanks Legionair. Mt only real mod is a Mac1 valve and a $20 red dot. At about 2-2.5 turns on the hammer screw I get about 70 shots per Co2 cartridge.

That’s all you really need for this fine shooter. It doesn’t “need” any modding, it’s just fun modding my cheap guns

 

[holo07]

 Very cool, now you have me thinking about tricking my 78G out. It is just stock now.

 

[Pale_Rider]

Very cool, now you have me thinking about tricking my 78G out. It is just stock now.

Go for it man! Especially if you want to shoot out a little further than 10 yards

 

[Bolero]

Hi Kevin...how Sexy can you make a 78G ?

Most folks like to keep them Original like when First Produced...

I think Custom Grips would be a Plus, Maybe some sort of Suppresor like a TKO...A Custom Trigger like the TKO 1911...and Definately a Reflex low mounted Red Dot, like a HoloSun....

Nothing to make a better shooter of it, shoots great as is... just to make it stand out a little more...

Let us know what you decide... 

Chuck

 

[Roboslug]

My only mods are a Mac1 valve and a red dot sight. I'm the original owner and the stock barrel is plenty accurate for me at 5 meters. No scientific data, but I believe that the Mac1 valve makes a huge difference. The rds was a recent addition. It was uber cheap and has only two brightness settings and took me considerable practice to get used to it. 

A bright dot is much like driving into oncoming headlights. I bought a second rds, a UTG from Bud's, for my C600 that has 8 brightness settings and it makes a world of difference. That sight will probably be moved the the SW78G this weekend.

 

[Pale_Rider]

Roboslug those grips look better than the walnut! 

You’re a patient man learning how to shoot with that 2 setting red dot. I would’ve gave up on it after a few minutes. I have a UTG micro red dot that is worlds better than the cheap “Walther” ones I had. It doesn’t have different types of dots to choose from but the dot is crisp and it has a push button to cycle thru the brightness settings. It even conveniently remembers your last brightness setting, just push the button and you’re ready to go

 

[jkingrph]

My only mods are a Mac1 valve and a red dot sight. I'm the original owner and the stock barrel is plenty accurate for me at 5 meters. No scientific data, but I believe that the Mac1 valve makes a huge difference. The rds was a recent addition. It was uber cheap and has only two brightness settings and took me considerable practice to get used to it. 

A bright dot is much like driving into oncoming headlights. I bought a second rds, a UTG from Bud's, for my C600 that has 8 brightness settings and it makes a world of difference. That sight will probably be moved the the SW78G this weekend.

Where does one locate a rail mount like that for a 78G. Been looking through the internet and nothing so far?

 

[Pale_Rider]

 

Where does one locate a rail mount like that for a 78G. Been looking through the internet and nothing so far?

https://www.ebay.com/itm/smith-and-wesson-79g-78g-picitanny-rail-ready-to-ship-/174526739396

 

[Roboslug]

Roboslug those grips look better than the walnut! 

You’re a patient man learning how to shoot with that 2 setting red dot. I would’ve gave up on it after a few minutes. I have a UTG micro red dot that is worlds better than the cheap “Walther” ones I had. It doesn’t have different types of dots to choose from but the dot is crisp and it has a push button to cycle thru the brightness settings. It even conveniently remembers your last brightness setting, just push the button and you’re ready to go

Thanks, Vern doesn't make a set of bad looking grips. 

 

[jkingrph]

Where does one locate a rail mount like that for a 78G. Been looking through the internet and nothing so far?

https://www.ebay.com/itm/smith-and-wesson-79g-78g-picitanny-rail-ready-to-ship-/174526739396

Thanks, I googled every description I could think of and looked at ebay and nothing came up. This helps. I have two of those guns and want to try a red dot on one and see how much better I might be able to shoot. My old eyes are not the best, and a red dot has helped some shooting a little micro 9mm.

 

[Pale_Rider]

Thanks, I googled every description I could think of and looked at ebay and nothing came up. This helps. I have two of those guns and want to try a red dot on one and see how much better I might be able to shoot. My old eyes are not the best, and a red dot has helped some shooting a little micro 9mm.

No problem. The red dot should help shoot better. I like putting a 2x pistol scope on there too

 

[Rickem88]

Y’all have good taste. Robo, me and you got the same green camo laminated grips in our 78g’s but mine have incurred some chipping and wish I’d gone with solid wood.
I have a older worn 78g and one that looks right out of the package. The older one is dialed and lethally accurate but the mint one wants me to raise those rear sites quite a bit to dial in the sites. What could be causing this? Do I need to shim the front to raise the barrel?

 

[ctshooter]

Nice looking pistol. I picked up a 79G here for an excellent prize. No box or manual, but in near new condition. I don't think it had been fired in a decade or more. All the seals were completely dried up so I picked up a reseal kit that came with a peek poppet valve, gave the barrel a good cleaning and polished it up and it's shooting the 7.87gr 177s @ 400fps with just 1 turn in on the hammer spring.

It's a very good pellet pistol - much better than most current CO2 pistols. Definitely one that should be part of any vintage collection.