by Tom Gaylord
Writing as B.B. Pelletier

The history of airguns

This report covers:

  • Old joke
  • The answers
  • Summary

You read this blog and you learn things — or at least you say you do. You tell me the historical articles are the best, because they teach you all about how airguns developed.

Old joke

To appreciate this joke you need to know something about domestic rabbits. They eat processed food that’s been compressed into little pellets, and when they eliminate it, the stuff that comes out also looks like pellets.

So the joke goes like this. One guy gives the other some rabbit pellets (the bad kind) and tells him they are smart pills. The second guy eats one and says, “These taste like poop!” To which the first guy responds, “See? You’re smarter, already!”

Now, let’s see if you’re smarter for reading this blog. Here we go.

1. At a gun show a guy tells you his breakbarrel rifle was shooting 1400 f.p.s., but he cut 10 inches off the 16-inch barrel to reduce friction and tuned it so it’s now doing 1700 f.p.s. What do you say?

2. A guy tells you he shoots .22 caliber pellets in his Smith & Wesson revolver that’s a .22 long rifle. He uses percussion caps in special brass shells he made on his home lathe to launch the pellets and he gets 2-inch groups at 25 yards. What do you think?

3. A friend wants to modify his new precharged rifle for hunting. He wants to cut the barrel down from 19 inches to 10 inches and shorten the reservoir tube to make the gun 30 inches long, overall. That will make it easier to handle in the woods. He asks you how he can also increase the velocity of this gun from 1100 f.p.s. to 1300 f.p.s. with the heavy pellets he wants to use.

4. A fellow at the gun club wants to invent a new kind of airgun, and has come to you for advice. This gun will have a screw ram on the end of the CO2 reservoir that he tells you is for boosting the pressure of the CO2 by reducing the volume inside the reservoir. Just turn the screw in and the volume is reduced. He wants to know if he reduces the volume inside the reservoir by 25 percent, how much will the gas pressure increase?

5. A followup question from the same guy — If he can boost the CO2 gas pressure by 25 percent, how much faster will his gun shoot?

6. A guy you know is fascinated by the Hodges catapult gun. He read somewhere that it could launch heavy lead balls at 350-400 f.p.s. If he builds a much stronger gun that’s similar to the Hodges but can accept many more elastic bands, how many bands do you think he’ll need to get his gun up to 800 f.p.s.?

7. A local gun store heard that you are an airgunner and they called to ask you a question. Their gunsmith wants to make adapters for .17 Hornet rifles that allow them to shoot .177 pellets using the power of small pistol primers. The adapter would look just like a .17 Hornet cartridge, only it would have a pellet in the end where the bullet normally goes. He reckons it would be a good cartridge to use on squirrels when he’s out hunting coyotes. They want you to come in and chat with the gunsmith, to help him figure this out. They’ll buy you a steak dinner for your trouble.

8. You spot an old breakbarrel on a table at a flea market. You don’t recognize the model, but the wood looks like dark walnut and the metal is all blued, much of which has worn off from use. One clue to the age is the fact that the buttstock ends at the back of the action. There is no forearm on this gun. It’s a .177, but it’s only marked 4.5mm and the letters D.R.P. There were other words on the gun but it looks like they have been polished off. The seller tells you he used to shoot it when he was younger, but it lost most of its power and he stopped shooting it about 10 years ago. What can you tell me about this air rifle?

old air rifle
What is this old air rifle?

9. The seller wants $25 for the rifle. Is it worth that? Should you buy it?

10. You see a small metal pistol in a glass case in a curio shop. It’s marked $10. There are threads in the bottom of the grip. The shop owner tells you she thinks the threads are to attach a water hose to the pistol. She thinks it came from a carnival game where people shot water into a clown’s mouth to make a monkey climb a ladder. The person whose monkey reached the top of the ladder first won a small prize.

old pistol
You see this old pistol in a case. What is it?

screw threads
Because of the screw threads at the bottom of the grip, the owner thinks the gun was attached to a water hose in some kind of carnival game.

The answers

Here is where we find out what you have learned about airguns. You may find you know more than you thought. If you want to test yourself, try to answer all the questions before reading this.

1. At a gun show a guy tells you his breakbarrel rifle was shooting 1400 f.p.s., but he cut 10 inches off the 16-inch barrel to reduce friction and tuned it so it’s now doing 1700 f.p.s. What do you say?

You don’t say it aloud, but this guy is lying. No spring piston airgun has ever shot 1700 f.p.s. Maybe someone saw a chronograph error and believed the number, or maybe they had a powerful fuel-air explosion inside their spring gun’s compression chamber. That turns the gun into a firearm, so it no longer qualities as an airgun. Airguns do not shoot this fast.

Next — how the heck is he cocking this gun? If the barrel is only 6-inches long the cocking effort must be several hundreds of pounds! Does he address that at all, or is he ignorant of the physics involved? Any gun that starts out shooting 1400 f.p.s. (which is probably also an exaggeration) already cocks with a lot of effort.

Finally — ask him what he did to tune the rifle. Compare what he says with what you have learned from reading this blog. I bet he misses a step or two (or ten!).

2. A guy tells you he shoots .22 caliber pellets in his .22 long rifle Smith & Wesson revolver. He uses percussion caps in special brass shells he made on his home lathe to launch the pellets and he gets 2-inch groups at 25 yards. What do you think?

Ahh — the dream of all who are new to airgunning. They wonder what a percussion cap or primer would do when it pushes a pellet.

What they ought to do is wonder how airgun barrels differ from firearm barrels. They are not the same size at all. A .22 pellet rifle barrel is not the same as a .22 rimfire barrel. Heck — .22 rimfire barrels are’n even the same size as .22 centerfire barrels!

I think he is confusing the 25 yards he says he is shooting with 25 inches. He might be able to hold them his pellets in 2 inches at that distance.

3. A friend tells you he wants to modify his new .22-caliber precharged rifle for hunting. He wants to cut the barrel down from 19 inches to 10 inches and also to shorten the reservoir tube to make the gun 30 inches long, overall. That will make it easier to handle in the woods. He asks you how he can also increase the velocity of this gun from 1100 f.p.s. to 1300 f.p.s. with the heavy pellets he wants to use.

Sure, cut that barrel off and see what it does! For starters, it will reduce the velocity by more than half. But here is the real flaw in this guy’s logic. First he tells you what he is going to do, then he asks you to agree that he will be able to get a certain velocity from the shorter gun with certain pellets. If you talk to him long enough you will probably discover that he doesn’t even own a precharged rifle yet. He’s just sitting in his easy chair, designing universes he would like to inhabit. If you tell him it will work, he’ll buy the rifle, screw it up and blame you for the results. “You told me it would work !”

4. A fellow at the gun club wants to invent a new kind of airgun, and has come to you for advice. This gun will have a screw ram on the end of the CO2 reservoir that he tells you is for boosting the pressure of the CO2 by reducing the volume inside the reservoir. He wants to know if he can reduce the volume inside the reservoir by 25 percent, how much will the pressure increase?

This is the old, “If I put more gas in the tank, how much faster will my car go? argument. First let’s address the science. CO2 pressure isn’t achieved by compression. It’s achieved by the temperature of the gas. You can reduce the internal volume of a CO2 tank by 50 percent and not raise the pressure. All that will happen is that more CO2 gas will condense into liquid. When you get past 90 percent liquid in a reservoir you have what is known as a bomb. There is nowhere inside the reservoir for the gas to go if the temperature rises. A rise of just a few degrees can multiply the internal pressure many times over.

The CO2 gas pressure inside a 12-gram cartridge is the same as the pressure inside a 500-cubic foot tank when both are at the same temperature.

5. A followup question from the same guy — If he can boost the CO2 gas pressure by 25 percent, how much faster will his gun shoot?

CO2 expands slower than compressed air. So the maximum barrel length for best velocity is not nearly as long as it would be for a barrel using compressed air. This fellow would do himself a favor to learn more about CO2, as it behaves in airguns, before embarking on this project.

6. A guy you know is fascinated by the Hodges catapult gun. He read somewhere that it could launch heavy lead balls at 350-400 f.p.s. If he builds a much stronger gun that’s similar to the Hodges but one that can accept many more elastic bands, how many bands do you think he’ll need to get his gun up to 800 f.p.s.?

The catapult gun is fascinating. I wrote a report about catapult guns that explains how springs have to be optimized for the task they do. Read that.

Elastic bands all have spring rates — the rate at which they contract after being stretched. Adding more bands doesn’t affect this rate. More bands may launch heavier balls, but they won’t do it any faster.

7. A local gun store heard that you are an airgunner and they called to ask you a question. Their gunsmith wants to make adapters for .17 Hornet rifles that allow them to shoot .177 pellets using the power of small pistol primers. The adapter would look just like a .17 Hornet cartridge, only it would have a pellet in the end where the bullet normally goes. He reckons it would be a good cartridge to use on squirrels when he’s out hunting coyotes. They want you to come in and chat with the gunsmith, to help him figure this out. They’ll buy you a steak dinner for your trouble.

Another Michelangelo in the making! Read the answer to number 2. This is the same problem in reverse. A .17 Hornet bullet measures 0.172-inches in diameter. How well do you think a .177 pellet will do in that barrel? A little tight?

Also why can’t he just shoot the squirrels with the .17 Hornet? What — is that now an elephant gun? Maybe he just wants a good safety range, since he will be shooting into the trees. Tell him to get a real air rifle. Try to get the steak dinner before you spill the beans, though!

8. You spot an old breakbarrel on a table at a flea market. You don’t recognize the model, but the wood looks like dark walnut and the metal is all blued, much of which has worn off from use. One clue to the age is the fact that the buttstock ends at the back of the action. There is no forearm on this gun. It’s a .177, but it’s only marked 4.5mm and with the letters D.R.P. There were other words on the gun but it looks like they have been polished off. The seller tells you he used to shoot it when he was younger, but it lost most of its power and he stopped shooting it about 10 years ago. What can you tell me about this air rifle?

I hope you got this one. The buttstock is one clue that tells you this is probably a pre WW 2 gun. But D.R.P. cinches it, since that stands for Deutsches Reichspatent. I think you will only find that stamped on airguns made before the end of the second world war. The 4.5mm marking without the .177 caliber is another clue that this gun was probably made for German use.

Being that old the piston seals are undoubtedly leather. The breech seal will be leather as well, and you can see that. The power loss was probably due to the seal drying out, and as long as the gun hasn’t been abused, it should come back to life with an infusion of oil down the transfer port.

9. The seller wants $25 for the rifle. Is it worth that? Should you buy it?

It’s worth all of $25 and more. Until we hold the actual gun in hand it’s difficult to say how much, but $25 is a no-brainer.

Buy it if you want it. But don’t buy it if you don’t plan to do something with it. Ask RidgeRunner about this. He anguished a long time at an airgun show over an old gun like this that cost a lot more than $25. He did buy it and I believe he is very happy with his decision.

10. You see a small metal pistol in a glass case in a curio shop. It’s marked $10. There are threads in the bottom of the grip. The shop owner tells you she thinks the threads are to attach a water hose to the pistol. She thinks it came from a contest-type of carnival game where people shot water into a clown’s mouth to make a monkey climb a ladder. The person whose monkey reached the top of the ladder first won a small prize.

This is a true story. My wife, Edith, did exactly this at a local flea market. and was told the water pistol story She offered $5 and the dealer gladly took it. Today that 1872 Haviland & Gunn BB pistol gun sells for around $800-1200.

apart
When I disassembled Edith’s purchase, I discovered it was really an antique spring-piston airgun.

Summary

Today has been a test to determine where you are on your journey with airguns. The more things you spotted, the better you understand airguns, in general. Don’t be discouraged if you didn’t get them all. This hobby is large and diverse, and you can spend a lifetime learning things. In my opinion, it’s time well spent.