There is a large selection of air rifles available to predator hunters these days, ranging from the standard airgun calibers of .22 and .25 going all the way up to the massive .72-caliber big bore.  Between the traditional small bores and the growing range of big bores, sits an interesting group of rifles I call the mid-bores — .257-, .30- and .35-calibers. The reason I place these guns in a separate category is that they are designed to operate at a power level between the standard calibers used for small game and the high-power levels of the true big bores used for big-game hunting. 

When discussing airguns, it’s important to remember that caliber selection and projectile performance is different from firearms. What I mean by this is that a 120-grain .35-caliber slug might generate 100 fpe (foot-pounds of energy) in one rifle and the same slug in a different model of gun might generate 250 fpe, as the power output is dictated by the gun and not the ammunition. I’ll come back to this later, but for now let’s assume that .25 and lower calibers are usually designed to generate under 90 fpe, and guns in the .45- to .72-caliber range might generate anywhere from 300 fpe to 1,200 fpe. 

For most predators, especially coyotes, a .25-caliber rifle putting out 90 fpe is too low to have confidence in consistently making a clean kill. That is not to say it cannot drop a ’yote, but unless you can place the shot with surgical precision and have the discipline to take only close-range head shots, you will not be consistent. On the other hand, a .50-caliber big bore generating 600 fpe with a heavy slug is going to blow right through a song dog standing broadside at 75 yards, not to mention having a low shot count, louder report and usually a much heavier and unwieldy rifle. But many of the mid bores fit the predator hunting requirement perfectly with respect to both form and function. 

A .30-caliber rifle puts out about 100 fpe (at the lower end of the power spectrum), with the typical higher power model .357s getting up into the 200 fpe range. Some can go higher than this, but I think 200 foot-pounds of energy is a respectable power output in this caliber. The advantages are that these guns tend to be flatter shooting, have the terminal performance to anchor a coyote with a broadside shot at 75-100 yards, offer a higher shot count, tend to be quieter and are built on more compact frames.

Projectile Preferences

One of the first considerations when selecting a mid-caliber airgun is to decide what type of projectile you want to shoot. The options are using a Diabolo-style domed pellet, which looks and acts like a conventional airgun pellet on steroids, or slugs. While many guns can shoot both, they tend to be optimized toward one or the other. Rifles designed to operate at lower power generally favor pellets, while guns producing higher power output work better with slugs. Each of these projectiles, when coupled with the appropriate shooting platform, offers advantages and disadvantages. 

The flared skirts of pellets expand under pressure and engage the rifling of the barrel, efficiently utilizing a lower operating pressure. Air rifles designed for pellets are often compact, have a larger shot capacity and a smoother and easier cocking mechanism. My experience with out-of-the-box magazine-fed guns is that pellets often feed easier and more reliably than slugs. This is not always the case, and guns that don’t feed slugs smoothly might do so after a tuning. Pellets are not as ballistically efficient as slugs, which might be a disadvantage based on intended usage. Diabolo pellets destabilize at supersonic velocities, they shed velocity faster and do not penetrate as well as slugs. 

Because of this, if the intention is close range suburban hunting, pellets are a great option. The range is more limited and the chance of over penetration is reduced, yet the knock-down power can be impressive. Guns designed for lower power applications with Diabolo-style pellets usually have a better shot count and are frequently quieter. The downside is suboptimal ballistic and terminal performance when the range is extended. 

Slugs on the other hand, demonstrate ballistic performance that is comparable to a firearm: They retain energy better, are more stable and offer better penetration at greater distances than is achieved with a pellet. So, if the intention is reach out farther, a gun optimized to shoot slugs might be a better option. These guns are often, but not always, louder than guns designed to operate at lower power levels. I prefer the powerful slug guns in more wide-open spaces where a louder sound signature is a non-issue. And it is worth noting, even these guns are quieter than a standard .22 LR. 

Most air rifles in .30- or .35-caliber can use either pellets or slugs, especially now that there are manufacturers offering hybrid airgun slugs designed to work in a caliber-matched rifle. These slugs can be round-nose or hollow-points and feature a concave base that functions along the same lines as a Diabolo pellet skirt. Many guns will shoot acceptably well with either type of projectile, maybe not optimally with both, but still provide a usable platform for slugs or pellets depending on the hunting application. 

There are rifles available that can optimally utilize either pellets or slugs without tradeoffs, designed to accept either slug liners for the standard barrel, or use interchangeable barrels designed specifically for shooting slugs. Liners and interchangeable barrels are designed with a twist rate to improve slug performance and generally allow for power adjustments to optimize output dependent on the projectile. 

I have several mid-bore rifles in my collection that are used for different applications. My suburban predator rig is the Evanix .357-caliber Sniper carbine, topped with the ATN X-Sight 4K Pro night-vision scope. This rig is beefy, but is also compact, adjustable and carries well. I have a suppressor for it if I’m hunting an area that is noise sensitive but opt for the shorter length in most cases. The gun loves the JSB 81-grain round-nose Diabolo pellet, and has accounted for several coyotes, foxes and raccoons inside of 50 yards. The sidelever action cycles a cassette magazine that allows for fast follow-up shots when needed. 

Another gun I’ve been using recently is the Hatsan Factor in .357-caliber, a tack driver optimized for the 82-grain Hatsan Air Boss .35-caliber pellet. This rifle is regulated and features adjustable power, has a very light and tactile trigger and is very consistent. It is also quiet, due to a fully shrouded barrel, which is a nice feature when hunting near town. This magazine-fed rifle uses a sidelever action, which is my favorite mechanism for a predator gun, because it is fast and easy to cycle. Though this rifle is at the lower end of the power spectrum in .35s, I still like it as a mid-range gun because I can reach out to 75 yards for precise shot placement. 

An example of a great convertible hunting rifle, which can be optimized for either pellets or slugs, is the FX Crown. My Crown is a .30-caliber and has a variety of barrels, including one with a liner specifically designed for shooting the FX Hybrid slug. This sidelever, magazine fed, whisper quiet rifle is another one of those mid-power precision shooting pieces that makes the mid-bore air rifle the perfect tool for thinning out predators in more built-up areas where a centerfire isn’t an option.

The upper end of the power spectrum in the mid-bores is populated by guns designed to use heavier slugs and fall into the gray area between predator and big-game hunting. An example is the classic Quackenbush .308-caliber, a bolt-action powerhouse that has stacked up both predators and larger game for me over the years. This rifle is a single shot that can only be used with lead slugs, and this one has been dialed in for a 120-grain round-nose. This rifle is putting out close to 200 fpe, which can reach out to 120 yards for those dogs that just will not come in. The price of this power is a lower shot count, and it is loud! Another rifle that I use a lot and would put in the same category, is the Airforce Texan in .308- and .357-calibers. The Texan has a higher shot count, a shrouded barrel as an option and is more widely available. 

I mentioned the .257-caliber earlier, and this is a very interesting caliber that I’ve used only in the AirForce Texan for long-range target shooting reaching out to 200 yards. While I typically use airguns for closer-range hunting, this rig and a 70-grain slug could certainly serve as a long-rang predator setup. 

So even though you could use a lower power small bore or toss a serious chunk of lead down range through a monster big bore, the mid bores in .257- to .35-calibers hit it just right when the objective is to bag a coyotes, bobcats or foxes. The gun, caliber and type of ammo you choose will depend on your specific needs. If you plan to clear out the coyotes on a golf course or around a housing development, go for a lower-powered gun with a shrouded barrel, set up for Diabolo pellets. But if the intention is to go out calling on a ranch in South Texas, go for the high end of the power spectrum and a heavy slug. But if you’ll be covering both scenarios, think about a rifle with a slug liner or interchangeable barrels to optimize your shooting platform and provide more flexibility.