The powerplant end of the Big Bore 5-foot .62 calibre blowgun. Below, the 2-foot slide-on extension turns it into a 7-foot blowgun.

Hunting darts. From top: two film-cone darts made by a German blowgun enthusiast, Cold Steel Mini Broadhead dart, Cold Steel Razor Tip Broadhead, home-made disk-cone broadhead.

The bow is probably mankind’s best-known ‘body-powered’ weapon, but the simple blowgun is also widely used in certain parts of the world and blowgun hunting is a growing sport. USA blowgun expert Jock Elliott contributed this article on the construction and use of the blowgun.

Want to put your skills to the test with a different kind of man-powered weapon? Give blowgun hunting a try. Blowguns have been around for hundreds, if not thousands of years, and have been used for hunting by indigenous people in North and South America, Asia, Africa, and Europe. With a blowgun, you can take small game such as birds, squirrels, rabbits, pan fish, and snakes. In his book A Sporting Chance Daniel Mannix tells of successfully hunting a wildcat, woodchucks, and pigeons with a blowgun without the use of poison. He also killed a deer using darts with curare. Today, it is common for researchers, veterinarians, and biologists to use blowguns to tranquilise wildlife.
The blowgun is virtually silent and requires no movement that would reveal your presence. It’s mechanically simple, highly reliable, and easy to carry. The darts are inexpensive to buy or easy to make. And blowguns are easy to use. Just place a dart in the tube, quickly blow into it, and the dart comes flying out the muzzle. That’s all there is to it.
An acquaintance of mine, Avery Scoville, has been hunting with blowguns for almost 20 years. “I was 13 when I got my first blowgun, a .40 calibre, but I had very limited success with it,” he says. In college, Scoville read up on blowguns and how to improve success. “Really good broadheads are the key to getting small game,” he says. Scoville generally tries to get within 20 to 25 yards. “I just don’t feel confident beyond that,” he says. “I usually aim for a heart/lung shot. Even if your aim is a bit off, the dart should slow the target down enough for a second shot. If you miss, half the time the game stays there and lets you shoot again. I haven’t found any other weapon that lets me do that.”
Scoville says, “I would often take my blowgun with me into my hunting blind while bowhunting for deer. I could then pass the time by silently shooting at small game that happened by. I wouldn’t have to worry about making any noise or movement that would alert any nearby deer to my presence.”
When my friend Lynn Thompson was in sixth grade, a missionary from Brazil visited the church that Thompson’s family attended. “He got up on the platform and showed us this handmade blowgun from the Amazon,” Thompson says. “He shot across the entire church and put six darts into a single acoustical tile. That kindled my interest.”
Years later, as the president of Cold Steel, Inc., Thompson purchased J.W. MacFarlin Company, which manufactured .625-calibre magnum blowguns. Soon Cold Steel had brought out its own line of Big Bore™ blowguns.
Thompson has hunted with Big Bore blowguns in the U.S. and Africa, taking such game as doves, quail, rabbits and squirrels. “You can make meat with a blowgun,” Thompson says. “You can take American pheasant or turkey with headshots if you’re good, but you need to practice every day if you want the skill to hit game in the head at 10 yards. When you can hit a 30 millimetre circle nine out of ten times, you have the skill to make a lot of head shots.”
If you’d like to try blowgun hunting, one of the first things to consider is the size of your lungs. Human lungs hold around 240 to 365 cubic inches of air.   Some of that air remains in the lungs between breaths, though, so actual useable lung capacity is between 100 and 180 cubic inches for a child and about 220 to 300 cubic inches for an adult. 
A rule of thumb for blowgun size, for good dart acceleration, is that you want the volume of the blowgun tube to be a maximum of 1/10th of your available lung capacity. This means that you want the volume of your blowgun to be no more than 22 to 36 cubic inches, depending upon your size (assuming you are an adult).
A four-foot-long .625-calibre blowgun has a tube volume of 14,7 cubic inches; a five-footer, 18,3 cubic inches, and a six-footer, 22 cubic inches. A seven-foot-long .625-calibre blowgun has a tube volume of over 25 cubic inches. 
The three most common calibres of blowguns are .40, .50, and .625 (inches). My experience, and the experience of all blowgun hunters that I have contacted, is that .40-calibre blowguns are completely unsuitable for hunting. There are no good .40-calibre broadheads, and wire darts simply are useless for inflicting lethal damage.
The minimum size for a hunting blowgun is .50 calibre. Commercially available broadheads and mini-broadheads that fit .625-calibre blowguns can be adapted for use in .50-calibre tubes, if necessary.
Another thing to think about is tube length versus convenience.  A longer tube offers a longer sight radius. Even though a blowgun doesn’t actually have sights, I find the longer tube makes it easier for me to get my aim right. But on the flip side, as tube length increases, its handiness for transport decreases. A seven-foot one-piece blowgun of any diameter is very unwieldy for transport in any kind of vehicle. In addition, long tubes tend to sag under their own weight. If you want a long blowgun, it is best to secure a take-down model.
Once you have determined the calibre and length of your blowgun, there are two ways to go: make one or buy one. Making a blowgun is fairly easy and Avery Scoville gives excellent directions on his website, http://sites.google.com/site/blowgunhunter/. He made his own seven-foot take-down blowgun from electrical conduit (roughly .62 calibre) and made broadhead hunting darts from 1/8-inch wooden dowels for the shaft, paper for the tail cones, and number 11 X-acto blades for the broadheads. His website will walk you through putting together your own do-it-yourself blowgun.
If you would rather purchase a hunting blowgun, the best commercially available hunting blowguns, in my opinion, are those from Cold Steel (www.coldsteel.com). Cold Steel offers three different models of .625-calibre blowguns: a five-foot one-piece blowgun, a four-foot one-piece blowgun, and a five-foot take-down model. Any of these models can be lengthened by an optional two-foot slide-on extension. My personal favorite is the five-foot take-down model. It’s extremely well made and has the best joining mechanism of any two-piece blowgun I’ve seen.
The barrels are all fabricated of aircraft aluminum and come with an excellent high-flow mouthpiece, a removable ferrule at the muzzle that allows the whole thing to be used as a walking stick, and a quiver that slides onto the barrel.
A selection of hunting, target and stun darts comes with each Big Bore blowgun, and I have been very pleased with their performance.
Don’t underestimate the power of a blowgun. Avery Scoville reports sending his 20-inch hunting darts downrange at 185 fps using his seven-foot homemade take-down .62 blowgun. Using just 4 feet of his blowgun, he got 145 fps.
In my own tests with Cold Steel Big Bore blowguns and Mini Broadhead darts, I got 113 fps with a four-foot blowgun, 132 fps with a five-foot blowgun, and 153 fps with the four-foot blowgun with the two-foot extension added, but only 134 fps with the five-foot blowgun with the two-foot extension added. Clearly this was more than my lung capacity could handle.
In a DVD from Cold Steel, Lynn Thompson puts darts through ¼-inch plywood and hard-tanned 3/16-inch cowhide, and breaks ceramic mugs with stun darts. Inspired by his example, I set up a “tin” fruit can at 13 yards and fired an unsharpened mini-broadhead dart at it.
It punched through both sides of the can. I tried the same experiment with a Razor Tip Broadhead dart and while it penetrated only one side of the can, it made a hole nearly twice as wide.
If you want to get started on blowgun hunting, here’s what you need:
• A good blowgun of appropriate length. Most adults should be able to shoot a four- or five-foot .625-calibre blowgun.
• Sharp broadhead darts.
• Good technique. To get maximum velocity, purse your lips in the mouthpiece, put your tongue behind them, pressurize your lungs and mouth, and then suddenly remove your tongue – so that the air is expelled explosively (PWAH!).
• Excellent bushcraft. The closer you can get to your prey, the better.

For more information about Cold Steel Big Bore blowguns, call toll free (in the USA only) (866) 599-5085 or 817-599-5085 or email to: customerservice@coldsteel.com Business hours 8 am to 5 pm Monday to Friday CST. Saturday/Sunday closed. Cold Steel blowguns are also available from Sharp Edge Sharp Shooter in Sandton City, Johannesburg: www.sharpedge.co.za.