Smith & Wesson 78G and 79G target pistols: Part 2
by Tom Gaylord
Writing as B.B. Pelletier
My S&W 78G pistol.
This report covers:
- Something special
- RWS Hobby
- Shot count
- Little trick
- 12.5-gram CO2 cartridges
- Crosman Premiers
- H&N Baracudas
- Trigger pull
Before we begin let me remind all of you that today is the 3rd of June — another sleepy dusty delta day. Stay away from Choctaw Ridge!
The comments to Part 1 of this report show that there are many airgunners who appreciate these air pistols. I mentioned in Part 1 that after 1980, Daisy took over the manufacture of these pistols and designated them models 780 and 790. In 1984 they brought out the silver-colored Daisy model 41 that was made only in that year. According to the Blue Book of Airguns the 780 was made from 1982 to 1983. The 790 was made from 1982 to 1988.
One of our readers — 45Bravo — reseals these guns, as long as they haven’t been modified or “customized.” He knows the S&W and the Daisy guns quite well, and he is working on a guest blog to tell us the differences between them. I have already learned some things just by reading the draft of his report. There isn’t a lot of information available on the Daisy guns, so this series will be of value to everyone who is interested in these airguns.
Today we will look at the velocity of my 78G, which is the .22 caliber version of the pistol. I mentioned in Part 1 that my pistol has been modified, so don’t compare it to a stock 78G. Mine shoots a lot faster and gets fewer shots on a CO2 cartridge. The man who did the work on this one no longer works on them, as far as I know, but from what I’m reading while researching, they aren’t that hard to reseal, as long as they haven’t been modified.
Part of the soup-up was to thin and shape the normally fat rounded bolt probe. This allows better gas flow.
I’ll start with a known lightweight lead pellet — the RWS Hobby wadcutter. At just 11.9-grains, you know this one will be fast in any pellet gun. In the 78G Hobbys average 521 f.p.s. for the first 10 shots. I would expect a stock pistol to shoot them at 375-395 f.p.s. My pistol is definitely fast.
The velocity spread ranged from a low of 511 to a high of 529 f.p.s. That’s a range of 18 f.p.s. which isn’t terrible for a souped-up gas gun. At the average velocity this pellet produced 7.17 foot-pounds at the muzzle.
But wait — there’s more! I remembered that this pistol had around 15 good shots on a CO2 cartridge, so I continued shooting Hobbys, to see what they might do. The second string (shots 12 through 22 because there was one shot that did not register in both strings) averaged 510 f.p.s. But let’s look at the string to see what’s really happening. Since I fired 11 shots in the first string, I will start this one with shot 12.
15………….Did not register
That string shows that the power is dropping by shot numbers 20 or 21. Therefore I say there are 20 good shots in a CO2 cartridge. Now, cartridges do vary, so you may get a few more or a few less shots, depending on the cartridge. But I’m going to do something I have never done before. I will shoot this cartridge empty.
36………….235 all the gas exhausted
There you go. Know what we have there? We have the difference in the shot count between BB Pelletier, who is looking for a very tight spread because he shoots at bullseyes, and Joe Average, who just keeps shooting as long as there is gas in the gun! BB says there are 20-21 shots in a cartridge and Joe says there are a good 35. They are both right, according to their own criterion.
I will say that by shot 25 I could hear the difference in the loudness of the shot. So I knew the pressure was dropping.
I’ll tell you another reason for continuing to shoot this airgun. Because the designers placed the O-ring on the gas cap where it’s under pressure, the gas cap will be difficult to remove until near the end of the gas. That’s because the o-ring under pressure will hold the gas cap tight. You will even see plier marks on the knurling of some gas caps because of this.
That o-ring was cream-colored when it was installed, but years of exposure to Crosman Pellgunoil has colored it reddish. When it’s under pressure it climbs out of its seat and presses tight against the inside of the pistol grip to seal the gas reservoir.
But that is unnecessary! When the gas pressure gets so low that you can hear the difference, you can exhaust the rest of it by pressing back on the cocking knobs — the reverse direction of how the gun is cocked. Then, if the o-ring material in the o-ring that seals the gas cap is correct, the cap will unscrew easily. If the material in the o-ring is incorrect (a hardware store o-ring, for example), it may have absorbed some of the gas under pressure and you may have to wait a couple hours for the gas to leak out before the cap can be unscrewed. The gas depressurization procedure is spelled out in the owner’s manual.
12.5-gram CO2 cartridges
I used to get criticized for writing that CO2 cylinders contained 12.5-grams of CO2. But back in the 1970s, some cartridges were actually listed that way. They probably held the same amount as cartridges do today — that was just what was on the box.
Yep — 12.5 gram cartridges.
And, speaking of things I used to get criticized for, how about my telling people to leave their guns under pressure went stored? Let’s read from the S&W manual.
There it is in print. The underlining was done by a previous owner.
Okay, we have seen the velocity with lightweight pellets; what about medium-weights? What will the pistol do with 14.3-grain Crosman Premiers? Well, Premiers averaged 480 f.p.s. The low was 464 and the high was 484 f.p.s. At the average velocity this middleweight pellet develops 7.32 foot-pounds at the muzzle. We expect something like that because pneumatics and gas guns will generate more power with heavier pellets.
Now for a heavyweight. The H&N Baracuda pellet weighs 21.14 grains. It averaged 397 f.p.s. for 10 shots, but remember — this was the second string of 10 fired on a CO2 cartridge. Shot number 1 went out at 412 f.p.s and shot 6 went out at 404 f.p.s. After that the gun never shot over 400 f.p.s. again. So the average would probably by around 406 f.p.s. if I tested the first 10 after installing a fresh cartridge. Not a big deal, but I thought you should know
I calculated the power based on 397 f.p.s. and got an energy of 7.4 foot-pounds. The relationship between pellet weight and energy held through all testing, but with this pistol all the pellets were very close.
The non-adjustable trigger breaks at 3 lbs., even. There is some travel before the break, but it’s not a bad trigger.
Personally I would prefer to have a pistol that’s rated at the standard power. Then there would be a lot more shots on a cartridge. I would also like a pistol with an adjustable trigger, because as I remember it, that was a very crisp and light trigger — almost Crosman Mark I-like. Maybe I will start looking for an early 79G, because I can’t remember ever owning one of them.
The Smith & Wesson air pistols are classics through and through. If a company today wanted to focus on a landmark design, they could do no better.