How powerful were the big bore airguns of the past?: Part 2
by Tom Gaylord
Writing as B.B. Pelletier
- My knowledge base
- Quackenbush Brigand
- Air cane
- Farco air shotgun
- Powerful enough to kill?
This report is for reader Zebra who asked me last week about the power of the antique big bore airguns. He said he read that some were used in battle and had the power to kill soldiers. I answered him and gave a link to the very first report of this airgun history series (Part 1, linked above). It was done way back on August 21, 2015 when this section was started. But I read that report and discovered that it really didn’t answer his question. I had explained how big bore airgun power was determined, but not how powerful the guns actually were. So I’m adding this Part 2 to get to the heart of the question.
My knowledge base
Before I start throwing numbers around, let me first tell you that today’s report is based on my actual experience. It’s not based on what I think or on mathmatical calculations.
My first experience with a big bore airgun was with a .375-caliber Brigand — the first big bore made by Dennis Quackenbush. He had made a replica kit of parts before that for people to build their own Paul air shotguns, but he didn’t sell them as completed guns. So 1996 when the Brigand came out was when things got real for me.
The Brigand operated on bulk CO2. A fill was good for 10-12 powerful shots as I recall. And the velocity for a 84-grain lead ball was 600-650 f.p.s. There, Zebra. That’s your first big bore velocity and my first teaching point.
After I experimented with my Brigand for awhile, I wondered how it would perform on air. Dennis made it strong enough to hold more pressure, so after checking with him I filled mine to 1,200 psi from a hand pump and got that same lead ball up to over 800 f.p.s. That’s my second data point/teaching point. CO2 may have the same pressure as air was compressed in the antique airguns, but the CO2 molecule is larger than the separate atoms in air, and therefore it flows slower through a valve. So — more velocity on air at the same pressure.
Yes, I do know that 1,200 psi is more pressure than CO2 commonly reaches. That would be 850 psi at 70 degrees F. But there wasn’t that much difference in velocity from air compressed to the two pressures (1,200 psi and 850 psi). As long as it was always air, the bullet went faster than it did on CO2.
Then I bought an antique air cane. It came with a smoothbore barrel only and that was .43 caliber. I operated that cane on CO2 exclusively because that was what my fill adaptor was set up to work with. I got velocities of about 625 f.p.s. from that cane running on CO2. Do you see the parallel, here? The cane was a larger caliber and shot a heavier lead ball (120 grains versus 84 grains) but it still made about the same velocity as the Brigand. The cane was smoothbore and the Brigand was rifled. But they had barrels of about the same lengths and they shot at roughly the same velocities. I’m being very loose with the facts in this explanation, but the numbers really were that close. Guess what that told me? The antique big bores (the cane was from the late 19th century) all perform similarly.
Farco air shotgun
Okay, let’s look at another big bore that’s modern and runs on CO2. The Farco air shotgun from the Philippines fires a 28-gauge shot cup (.51 caliber) of shot, but a .43 caliber lead ball can also be used. The balls are lighter than the shot charge and they average about 500 f.p.s. That’s slower than the Brigand and air cane, but it’s still in the same general region. But listen to this. When it shot a charge of shot that weighed 245 grains, it went out at 450 f.p.s. That’s just 50 f.p.s. less than the ball that weighed half as much! So the velocity was pretty much based on the gun, rather than on the projectile. There’s another teaching point, Zebra.
Big bore velocities vary more gun-to-gun than they do projectile-to-projectile — as long as we are just talking about simple non-adjustable firing valves. You asked about antique big bores and that’s what I’m talking about today. Throw in an AirForce Texan and everything changes. The Texan has the technology to change velocities, unlike the antique guns.
In Part 1 we learned about the science of splatology, which is the phenomenon where a lead ball of any size flattens the same amount when it hits a hard target at the same speed. So a .375 lead ball that hits an anvil at 350 f.p.s. flattens just as much as a .60 caliber lead ball doing the same thing. The splat that the larger ball leaves behind is wider across, of course, but the lead splats from the two different calibers appear identical. That means we can determine the impact velocity of a lead ball that that has struck a hard target just by examining the splat it left behind. In turn that means we can know what velocity a lead ball was traveling two centuries ago, just by examining a drawing of the splat it left behind.
There isn’t a lot of splatology data to examine, but what we have points to many antique big bore airguns shooting in the 500-650 f.p.s. range. Curious, isn’t it? No matter how we look at this, the velocity of antique big bore airguns always seems to fall within a narrow range. And that is another teaching point.
Powerful enough to kill?
Zebra also asks if the antique airguns he has read about were really powerful enough to kill a human. Where they used in war, as he has read?
At least one of them was. A 21-shot repeater called a Girardoni, after its inventor, shot a .47-caliber lead ball with enough force to kill a man at a distance of 100 yards. In the book, Smith’s Standard Encyclopedia of Gas, Air and Spring guns of the World, the author, W.H.B. Smith, reports of one instance where this happened. It was sometime in the late 1700s when an orderly sergeant was killed by a ball while standing next to a group of officers. The shot was not heard and no smoke from the powder was seen, but they were facing Austrian troops and they knew the Austrians had no fewer than 500 rifled repeating airguns.
If a .47 caliber ball hit a man at 400 f.p.s. it would have had enough energy to kill him if a vital organ was hit. While we tend to think of 400 f.p.s. as too slow to do much damage, we are thinking in terms of pellets. It’s very different when it’s a lead ball of considerable size. Elmer Keith slaughtered cows in the stockyards in Chicago with muzzleloading cap and ball revolvers that shot smaller balls just a little faster than that, and those balls would often pass through the animal from front to rear.
Zebra, and anyone else who was wondering about the power of the antique big bores, that’s about all I can tell you. You now know:
1. They mostly shot from 500-650 f.p.s. at the muzzle.
2. We can determine their terminal velocity from forensic evidence if a drawing of the splat remains.
3. We know the air pressure at which they operated (from Part 1) and that also tells us how powerful these older big bores were.
4. To get greater power they used larger, heavier balls.
When you think about it, we know a lot about the power of the old big bores.