Big-bore airguns have been around since the 1600s, but the past couple decades have seen a growing interest and significant development in the technology. Lewis and Clark carried a big-bore airgun on their Western explorations, but knowledge of these guns seemed to evaporate until recently. 

It was during the early 2000s that big-bore airguns built by an innovative craftsman named Dennis Quackenbush trickled into the market. These early rifles were available in .308- and .50-caliber, with the .457-caliber eventually becoming the most popular caliber in the line. I met Dennis in 2002, and along with Eric Henderson started using these rifles for hunting predators, wild hogs and exotics in Texas. In 2003, I used three Quackenbush rifles on my first hunts in South Africa. 

The guns I carried were the most powerful air rifles available at the time, including a .50-caliber that had been modified to generate 450 foot-pounds of energy. This represented a marked increase in the out-of-box specification for the rifle at that time, and I took kudu and several other species of plains game with it.

 

Increasing Popularity

Over the years, as interest in big-bore airguns increased, manufacturers introduced increasingly powerful guns to market. At first these were small scale production runs, but as interest surged and hunting regulations in many states evolved to allow the use of these gun, larger and more established manufacturers jumped in, and something of an airgun power race began. 

In the balance of this article, I am going to share information on three of the most powerful production airguns currently available. In the spirit of full disclosure, I will say that these might not be the most powerful airguns on Earth — there are custom guns and hotrod tuners modifying guns — so it is always possible that higher power outputs might be achieved. I would also mention that in my view, the most powerful does not equate to the best, in and of itself. The accuracy, shot count, consistency, reliability, ergonomics along with other criteria should be taken into consideration when choosing a rifle to meet individual needs. 

All these big-bore air rifles utilize a pre-charged pneumatic design that is powered by a high-pressure air charge. The rifle will have an on-board storage tank or reservoir that is filled using an external air source — usually a carbon-fiber tank filled at a dive or paintball shop or filled directly with a compressor. In the past, compressors were very expensive, however compressors designed to fill guns directly up to 4,500 psi are now available at a much lower price point. 

For these very powerful rifles, a fill pressure over 4,000 psi is commonly used, and depending on the rifle each fill will allow three to six shots before the on-board air storage must be refilled. Most big-bore airguns experience a reduction in pressure with each subsequent shot on a fill, resulting in a reduction in power and drop in point of impact over the shot string. Guns can be adjusted to minimize this effect or may use a device called a regulator to operate at a standardized pressure for each shot, which improves consistency. 

Big-bore airguns are available in many calibers, but arguably the most popular are .308, .357, .40, .457 and .50. Over the past couple years, one of the manufacturers I’ll present, has been using larger calibers such as .58 and .72. My favorite caliber has been the .457, but when discussing the most powerful guns the caliber will invariably be .50-caliber or larger. If you look at a particular model of rifle available in both .457- and .50-caliber, the latter will typically be 100 fpe more powerful.

 

Meet the Powerhouses

So, what types of power outputs do these guns generate? For many years, hitting 600 fpe was the holy grail that gunmakers strived for. In short order, the AirForce Texan .457, AoA .457 and Hatsan Piledriver .457 hit this mark or crept slightly past it. To put this in context, on my first hunt in South Africa I used the Quackenbush .50-caliber, generating 450 fpe to drop a kudu at 75 yards. A gun putting out 600 fpe was a significant step up in power output! After reaching the 600 fpe mark, manufacturers started implementing higher fill pressures, larger calibers, along with improved valve technology and materials, to push well past this power threshold. 

The three rifles I’ve selected as the most powerful production guns are based on both published specifications and my own experience with them. To this end, when a rifle is available in multiple calibers, I have opted for the one that produces the highest energy levels for that model. They are, the Hatsan Piledriver .50-caliber, the AirForce Texan .50-caliber and the AEA Zeus .72-caliber. In addition to extensive range work, I have taken deer and will hogs with all of them.

Hatsan Piledriver .50-caliber

The Piledriver from Hatsan has been my default hunting rig over the past few years. I have this rifle in .457- and .50-caliber but will focus on the .50. It is a bullpup design that incorporates a 480cc carbon-fiber tank into the forend. The tank charges to 4,300 psi (300 BAR) and generates five to six shots per fill at up to 810 fpe. It is a single shot, cycled with a smooth and ergonomic sidelever action that provides easy access to the loading port. A scope can be mounted on a 14-inch rail that accepts either Picatinny or 11mm mounts. There are also three Picatinny mounts in front of the forend to mount lights, lasers or other accessories. 

This rifle is heavy but well balanced and carries comfortably in the field. With an adjustable cheekpiece and buttstock, the gun can be set up to fit the individual shooter. There is a bit of recoil, and the gun generates a healthy report, but the weight of the gun does a good job of dampening the minor kick. The only change to the Piledriver I’d like to see would be to make it more compact and lighter. I have been experimenting with a modified .457 version using a shorter barrel and found that cutting down and recrowning the 33-inch barrel to 15 inches cost about 100 fpe but resulted in a much more compact rig that is 33 inches in length overall (LOA).

 

AirForce Texan CF .50-caliber

One of the first very high-power production big bores to hit the market was the AirForce Texan in .457-caliber, but it’s currently available in .257-, .308-, .357-, .457- and .50-caliber. The Texan CF Series in .50-caliber uses the company’s tried and true air-tank-for-a-buttstock design — a 250cc carbon-fiber tank that replaces the heavier and bulkier aluminum tanks used in the standard Texan configurations. The Texan is 54 inches LOA with a 34-inch Lothar Walther barrel and weighs in at about 8 pounds. The gun uses a sidelever cocking action and has an accessible loading port and very nice two-stage trigger. 

This rifle is as lightweight as these powerful big bores get, and I have used the gun in every caliber and configuration. The buttstock design does limit the adjustability and fit to some degree, but aftermarket stocks are available to tailor the fit. To optimize the Texan for my style of hunting, I opted to cut about 10 inches from the barrel and recrown it, making it one of the most ergonomic and packable big bores in my collection. However, as mentioned above, the trade-off is diminished power, and I lost about 100 fpe. When I did this modification to my Texan there was not a carbine version, but current guns in the lineup are available as carbines.

AEA Zeus .72-caliber

The most recent entry into the rarified air of the ultra-high power big-bore air rifle is from a company called AEA. Fans of these guns often debate whether the Texan or the Piledriver is more powerful, but any way you cut it they are close. However, when the .72-caliber AEA Zeus was released, this question became moot because this rifle generates up to 1,500 fpe. 

The Zeus .72-caliber comes in three configurations, 16-, 24- and 32-inch barrel versions. I’ll focus on the 32-inch version, which is the most powerful. The Zeus is a big gun, weighing in at 11.6 pounds and is 50 inches LOA. This traditionally styled sporter is cycled with a sidelever action and has a safety release built into the lever. The 660cc air reservoir fills to 4,500 psi, providing about three shots per fill with a high level of shot-to-shot consistency for an unregulated gun. I most frequently use the 24-inch version that weighs about 10.3 pounds while dropping the power down to 960 fpe. 

Any of these three rifles could be the perfect hunting rig for you, especially if having a powerful air rifle is high on your priority list. There is certainly nothing wrong with more power, but for me there is a question of the cost/benefit ratio. These rifles are all accurate, reliable and do a great job in the field. For my hunting needs though, I am fine with a gun generating 600 fpe, and if faced with increasing the barrel length and weight to gain 100 fpe, will opt for the more compact and lower-power version. But that’s just my preference. I make it a rule never to tell anyone which rifle they should buy. The best rifle for an individual is very subjective. What I will say, is that if you are looking for a big-game hunting rifle — especially one for taking the larger or more dangerous North American game — these three powerhouses should be on you radar screen.