Hunting With Big-Bore Airguns

Jim Chapman reviews new big-bore airguns for predator hunting and more.

Hunting With Big-Bore Airguns

Most readers who have followed the Airgun Advantage column over the years are aware that big-bore precharged-pnuematic airguns have been around for a long time.

Bavarian nobility in the 1600s, soldiers in the Napoleonic wars, and Lewis and Clark all used them. But even in their heyday, not many people had heard of pneumatic airguns — being very expensive, technologically advanced and difficult to manufacture when compared to firearms, they were available only to the very wealthy. They were more accurate and had a higher rate of fire than early firearms, but firearm technology caught up — accuracy improved and they were relatively simple to manufacture and logistically easier to handle in the field, which resulted in the big-bore airgun fading into history.

It would be a couple of hundred years later when they finally resurfaced, and arguably today is the golden age for big-bore airguns. While there were a few examples of major caliber CO2 guns coming out of the Philippines in the ‘70s, it was a boutique airgun maker named Dennis Quackenbush working out of a shop on his Missouri farm that innovated and essentially created the modern big-bore airgun. A small group of us started using Dennis’ guns to hunt predators and bigger game more than a decade ago. I was writing about them, Eric Henderson was producing videos, and we were bringing more people into the field to hunt as well.

As more hunters started using these guns and talking about them, the sport grew, and the demand for guns kept pace. Dennis always had more customers than he could supply, and the waiting lists were long. Other small-scale semi-custom and custom builders started to bring product to market, and eventually more of the major manufacturers came into the game.

Development has branched out to include guns that shoot in the lower power ranges of 90 to 120 ft./lbs., which are ideal for predator hunting, to guns in the 200- to 600-ft./lbs. range, which are ideal for much larger animals. In this month’s column we’ll have a look at what’s available for aficionados of the major-bore airgun today.

There are several technical considerations when designing a big-bore airgun. You need to beef up the action, find the right twist rate for the barrel’s rifling that is optimized for the projectiles and velocities the gun will work under, provide an air storage that holds a larger volume of air and in some cases operates at much higher pressures, and a valve that handles the pressures and air volumes and provides an efficient airflow to drive much heavier projectiles.

Air consumption is a major consideration, whether the gun is operating in the standard 3,000-psi range or has been set up to work at much higher pressures (up to 4,500 psi). The number of shots the gun will produce from a fill will depend on how much air is consumed, how large the onboard reservoir is, and what the concurrent pressure drop with successive shots is. This will also impact the shot-to-shot variability and resulting shift in point of impact.

Another aspect of the major calibers I find warrants mention is the difference between the true big-bore and mid-bore guns. Based on caliber alone, I consider mid-bores to be the .30s — the .303, .308, .357 calibers — and big bores the .40s on up. Generally the power output lines up with the big-bore being more powerful and the mid-bores less, but this is not always the case. Still, I find it a useful means of categorizing the guns and tend to use the mid-bores for predators and the big-bores for big game.

It has been said, “You can kill just about anything with any gun,” but I don’t think that means you should try. It might sound contradictory when as a proponent of airgun hunting I channel Robert Ruark and say, “Use enough gun.” But I have enough experience with big-game airgun hunting to have observed — the .30s under 150 ft./lbs. are great predator guns out to 100 yards, but marginal big-game guns. The .40s on up that produce 300 ft./lbs. or more are great 75-yard big-game guns. There are more powerful mid-bores and less powerful big-bores that are effective on big game in the right hands, though I tend to consider these more of a specialist’s tool.

The Quackenbush guns are the epitome of what a big-bore gun should be, offered in .308, .457 and .50, and occasionally a batch will be built up with other calibers available (my favorite DAQ is a .452 built to my specs). These guns are based on a workmanlike and proven design that is robust, reliable and over-engineered. When you get on the list and order your gun, you can decide on barrel length, caliber, power output and stock type, grade and finish. You still need to get on a list and wait, but no matter what the new wave of development brings to market, these guns are the benchmark against which I measure all others.

A primary builder of big-bores has been Sam Yang, and the guns are imported by Pyramyd Airguns in the USA. The company has been building production big-bores longer than any other manufacturer, and they represent the “everyman’s” big-bore. The company’s flagship design is based on the BigBore 909 platform, which now comes in .357, .457 and .50 calibers. Though I have taken a fair amount of big game with these guns, the design is a bit anemic out of the box. However, they can be tuned to deliver a lot of power while maintaining a fairly high shot count, and even with the tune are a cost-effective way to break into the sport.

Airguns of Arizona is the importer of some of the finest airguns on the market, but recently the company has made its first foray into manufacturing with a very powerful big-bore rifle. This gun has been the brainchild of my hunting buddy, Kip Perow, and he used the initial prototype to take a mountain lion and a bear this year, proving the gun’s ability to take larger predators. This .457 is probably the most powerful production gun to be had. The CNC machining results in a high-quality metal work, and the thumbhole stocks Kip sourced for these guns are outstanding in terms of aesthetics and ergonomics. This is one of the two new American-built big-bores that has grabbed my attention in a major way!

The other new big-bore that I’m very excited about comes from the American manufacturer AirForce. While on the surface it shares many similarities with AirForce’s stable of guns in the Condor/Talon/Escape line, it is in fact a completely new design with respect to valve assembly and the side-lever cocking action. This .457 handles heavy bullets very well and provides mind-blowing accuracy along with impressive power in the 450- to 500-ft./lbs. range. The inline design of the airtank, valve and barrel seems to produce an extremely efficient and consistent shot profile.

In the mid-bore category, Daystate’s Wolverine and FX’s Boss are guns designed to work only with the JSB manufactured .303 Diabolo pellets, unlike many of the other guns (with a couple exceptions) that are more frequently set up to shoot solid cast bullets. These guns are quite accurate, but at the lower end of the power spectrum — I use them on predators and take headshots at closer ranges. The advantages are that they are quiet and the carrying range is limited, so they are the perfect up-close guns. In addition, unlike the rifles shooting solid bullets, they are also a reasonable option for small-game hunting.

One of the grand old names in premium airguns is the now-defunct company Theoben, which was based in the U.K. One of the principles in that company has launched a new manufacturing operation based in Tennessee named Rapid Air Weapons and has introduced a mid-bore rifle under the moniker of the RAW 1000 HM in .357. The test rifle I was shooting was generating about 100 ft./lbs. with the JSB Diabolo pellets, and though I only got to use it on long-range prairie dogs, I’m anxious to take it out for predators in the coming months. It is a beautifully crafted rifle.

Evanix manufactures a number of .357 rifles that I have been using a lot over the last couple of years. They are based on Evanix’s semi-auto (full auto is an option outside the USA) and well-proven side-lever actions. The models include the Conquest, Rainstorm, Windy City, Sniper and even a bullpup design called the MAX-ML. These guns shoot the JSB and Eun Jin .357 pellets very well but can also handle shorter-length cast bullets. Using this action in various guns, I’ve taken javalina, feral hog, springbok, duiker and predators, not to mention Guinea fowl, prairie dogs, jackrabbits and other small game. I have been impressed by the accuracy and shooting characteristics of the guns, especially in combination with the JSB pellets.

Today is the golden age of big-bore airguns. There is a broader range of products available covering just about every hunting application, the guns are widely available, and while they are not inexpensive, the price has settled down and most hunters can afford the cover charge. And probably one of the most significant drivers is that there are more places available to hunt bigger game and predators with air-powered rifles than ever before — mountain lion, bear, coyote, bobcat, hogs, whitetail and mule deer, javalina, pronghorn and exotics are all available to airgunners, and more states are considering or acting to add airguns to the regulations every year. If you’d like more information on hunting with big-bore airguns, drop by my website or YouTube channel or shoot me an email. I’d be happy to point you in the right direction!


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