Part 1 History of a spring-piston airgun

This report covers:

  • First practical application
  • Giffard flubs
  • Gifford flub number two
  • Next?
  • Marketing misstep
  • From separate tanks to reservoirs
  • One final failure
  • CO2 cartridges
  • Bottlecap cartridges
  • Why this blog today?
  • Summary

If I say CO2 most of us get a vision of modern realistic air pistols, plus some rifles that use one or two 12-gram CO2 cartridges. But there is so much more to this power plant than just that! Today we will take a brief look at all that has transpired since the gas of carbonic acid, or carbon dioxide, has powered guns.

First practical application

Frenchman Paul Giffard produced the CO2 guns that bear his name today. He started in the mid-to-late 1870s and continued for several decades. He made his guns in 6mm and 8mm primarily, but other calibers are known to exist. There are both long guns and handguns and all load from a tap that I described for you in the report  titled How do taploaders work?

Giffard pistol
A Giffard pistol from the Malvern airgun show.

I have seen Giffard guns at airgun shows since I started going to them in 1993. There always seems to be at least one. The guns are very well made and feature light engraving, classic walnut furniture and deep bluing of polished metal. They were always priced at just over a thousand dollars, but today that has crept up to over three thousand.

I don’t know how many were made but I have seen at least 50, and by eliminating the guns I’ve seen more than once that’s at least 20. They are scarce but not rare.                               

Giffard flubs

There is a huge amount of misinformation about them, such as you drop a pellet of some compound into their tank and add water to get the gas. That would be acetylene, not CO2. The Pawn Stars (an American “reality” television show) brought in their “expert” who said the Giffard was NOT charged with CO2, but a liquid — carbonic acid!!! That was what carbon dioxide was called back in the 1800s when these guns were made. It’s the same as saying we don’t drink water, we drink hydro (from the movie, Waterworld).

The Giffard rifle or pistol has a removable tank that had to be sent back to the factory to be refilled. If you lived close to the factory, no problem. If not — problem. Keep that in mind, because the same business model reemerges in the 20th century and puts one company out of business.

Giffards were almost all hand made, so they were never cheap. And they are not cheap today.

Giffard flub number two

A British-made air tank allows Giffards to be fired with air instead of CO2. If you don’t modify the gun’s valve, the air pressure has to be held low, otherwise the valve won’t open. In a test of an 8mm rifle a 49-grain lead ball that CO2 pushes out at 600 f.p.s. but with air it goes over 1,000 f.p.s. That’s taking 50 foot pounds over 100 foot pounds.

So, based on just that, some auction sites are claiming 120 foot pounds for antique Giffard guns that can’t make half that. Don’t buy a Giffard to wallop your target. Buy it because it’s what you want. Buy a big bore if you want wallop.


Unlike spring-piston airguns that never had a break in production, but like PCPs that broke from the 1920s until 1980, nothing more happened with CO2 after Giffard until the 1930s. Crosman started experimenting with a model they called the 117. After WW II it turned into the model 118. The 117 was tethered to a large tank of CO2. The 118 stood alone with CO2 cartridges inside.

That model was followed by the 100-series rifles converted from air to use CO2 from a 4-ounce tank that hung under the action. These were called CG guns, for compressed gas. They used 4-ounce CO2 tanks made for large life rafts in World War II and a pellet rifle got hundreds of shots per tank.

The first guns had their tanks on a backward slant. Later guns had the tank hang straight down.

Crosman CG rifle
This straight tank model CG rifle is a later variation that began with the slant tank. All of this was to use the 4-oz. CO2 tanks that were surplus left over from the war.

Crosman’s idea was to promote league shooting at companies and organizations. There probably weren’t enough serious airgunners in those days to make it economically viable. But World War II had just finished and there wasn’t the fear of guns that we see today. That was in line with what was happening at the time, because bowling leagues were also popular in the 1950s. These leagues were as much for socialization of the employees as for sport and recreation, and companies embraced them as an early form of team-building.

Crosman gallery
This Crosman shooting gallery was for league shooting. This employer installed one for their employees. A straight-tank CG is clearly seen in the hands of the woman second from the left.

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Marketing misstep

But there were some missteps here, as well. Crosman must have thought, like Sheridan, that if they made the caliber proprietary they would corner the market on ammo sales, so many of the CG gallery guns were made in a .21 caliber that is not available on the market — then or now. Those guns were sold with complete gallery kits intended for league use. Try to buy some .21 caliber lead balls today.

They also made some CG rifles for direct sales to the public, but these were made in the far more common .22 caliber that met with public acceptance. There were already pellets available everywhere in this caliber. Filling the CO2 tanks was still a problem, but Crosman’s engineers solved that with adapters that allowed league gallery teams and presumably private individuals to purchase common fire extinguishers to fill their tanks.

gas tanks
The 20-pound CO2 tank on the right holds gas for many times the number of shots that the 3000 pound 80-cubic-foot aluminum scuba tank on the left holds.

From separate tanks to reservoirs

The supply of surplus tanks finally ran out, so the company had to do something different. They provided a tubular gas reservoir that ran parallel underneath the barrel of each gun. Thus was born in 1950 the model 114 in .22 caliber and the model 113 in .177. I covered the 114 in a three-part report. A separate fill tank was needed to fill these guns, so Crosman provided the model 110 10-oz. CO2 tank that came packaged with each gun. Oddly they required that tank to be returned to Crosman for refilling — remember Gifford?

But Americans found a way and made adaptors to connect those 10-ounce tanks to 20-pound fire extinguishers, plus they learned that a siphon tube inside the gas tank allowed it to stand upright while pumping liquid CO2 (yes, Pawn Stars, CO2 inside a tank is a liquid). That they learned from the beverage industry, with their post-mix systems (syrup and gas are mixed after leaving the tanks, hence a tank of soda syrup holds many times more drinks than can be put into a premix tank of the same size.

gas tank design
The siphon tube allows the CO2 tank to stand upright while pumping liquid CO2.

One final failure

In 1950 there was one last failure with the bulk-fill CO2 gun where the owner was required to send the tanks back to the company for refilling. The Winsel company brought out a pistol and they even provided a second tank and a cardboard mailing tube for the tanks return. Fat chance. The thought of returning a CO2 tank for filling is as silly as storing your electronic data in “the cloud.” Sure, it’s safe — until it isn’t! It’s safe as long as THEY keep it safe. Ooops — we lost your archived family photos. Sorry. To repay you for your loss your next month’s storage service is free. Folks, there is a reason why, when disaster strikes, the things people save first after people and pets are their photos.

Winsel gas pistol
The Winsel gas pistol was a failure in the 1950s because the gas tank had to be returned for refilling. Try returning one today.

CO2 cartridges

It was a short move from bulk-filled CO2 guns to guns that used cartridges. But which ones to use? Of the companies we know today Benjamin was first and chose the 8-gram cartridge. Actually Schimel was at least two years earlier, but they went out of business quickly.  Crosman and other companies followed in the 1950s with 12-gram cartridges. Nobody has yet used the 16-gram cartridge, and I wonder why.

Schimel CO2 pistol
The Schimel CO2 pistol was made around 1950 and used an 8-gram CO2 cartridge.

CO2 cartridges
There are the small three CO2 cartridges. From the left they are 8-gram, 12-gram and 16-gram. Notice the 16-gram cartridge is threaded. To my knowledge it hasn’t been used in an airgun yet.

The 16 gram cartridge will probably never be used in an airgun without good reason. It would make pistol grips too large. The Colt Single Action Army revolvers already have Colt 1860 grips that are a half-inch longer, just to accommodate the 12-gram cartridges. People don’t complain because they look right, but a true single action buff knows the difference.                                                                          

Crosman 150
Crosman’s 150 came out in 1954 and established the 12-gram world standard size for CO2 cartridges. After that the race was on.

Bottlecap cartridges

Unfortunately for airgunners there was a patent on the method of sealing the 12-gram cartridge. To get around it and avoid paying licensing fees, Crosman invented the bottle cap method of sealing the cartridge and it was problematic. Us kids from the 1950s remember that in a box of 5 Crosman Powerlets we were lucky if three of them held gas. That and the design of the airguns that used them was what gave CO2 the reputation for leaking.

Why this blog today?

If you watched the first two videos with Tyler and me talking about airguns for newcomers we discussed the realistic lookalike air pistols that exist today. Actually companies have been making realistic CO2-powered airgun for many decades. I guess it all started around 1959 with the Crosman Single Action 6. That revolver was realistic, but manufacturers, namely Umarex, have gone out of their way to make air pistols more realistic. They are so realistic today that even experts can’t distinguish them without close examination.


The CO2 powerplant has evolved with the hobby of air gunning over the years. It’s older than the modern spring-piston pellet gun powerplant but far younger than precharged pneumatics. At the present time it seems to be enjoying the replica role among airguns, but that could always change.

Some of you love this powerplant! Well today is your chance to tell the rest of us why.