When buying any new air rifle there are several relevant factors to consider; power, accuracy, loudness (or quietness depending on perspective), trigger characteristics, the guns physical dimensions and how it fits the shooter, etc. Another important item specifically related to precharged pneumatic airguns is online air storage capacity, which dictates shot count and therefore how many shots are available each time the guns air storage reservoir is filled.
For any given gun, the shot count is a balance between how much air the gun can store and how much it uses on each shot. I have two Webley Raiders in my collection, which are identical except for the fact that one is set up for the UK market (12 foot pound of energy (FPE) limit), and the other has been set for the maximum power I can get out of this rifle design (40 fpe). The 12 fpe gun gets 60 shots per fill and the 40 fpe gun gets 22 shots. In other words I choose to give up 38 shots per fill in order to get an additional 28 fpe. The only way to get a higher shot count while keeping the same performance (peak velocity/energy) would be to increase the volume of available air.
When hunting small game and varmint I often want to use a gun that generates maximum power (to stretch out the shooting range), and don’t always want to carry an extra air tank in my pack. The way to accomplish this is deceptively simple, store more air in the gun! But increasing the dimensions of the air reservoir can be tricky; it needs to be done so that the balance and shooting characteristics of the rifle are not compromised.
There are essentially three ways to substantially increase the onboard air storage; you can attach a large capacity air bottle to the forestock, incorporate a large capacity air bottle into the buttstock design, or do both. There are several guns on the market that use the forward mounted air bottle, the BSA Superten, the FX Boss, and the Daystate Wolverine Type B (whew, that’s a mouth full) being good examples of the breed. Less common are guns that use the air bottle as the structural basis for the buttstock, exemplified by the AirForce line of guns (the Talon and Condor) and the FX Verminator. These guns provide a very high shot count even when the guns are dialed up to provide the maximum possible power. The third configuration is a combination of the two, with a large volume air bottle forward and back.
I’ve used the forward bottle guns from BSA, Theoben/Rapid, Daystate, and more recently FX and Daystate. I think this is a good design when you want to tune a gun to deliver maximum power with big heavy pellets. All of these rifles will let you drive heavy projectiles at high velocities while maintaining a fairly high shot count, the actual number depending on the bottle volume (typically between 400 – 500 cc) and the power level set up for the gun. In some of the earlier models (like the BSA Superten) I didn’t really like the feel of the bottle as the stock didn’t cover it, though I still found it possible to shoot accurately. But the newer guns, especially the Daystates and FX guns, tend to have more ergonomically designed stocks that either seamlessly dovetail into the bottle, or actually forms a shell that covers it.
The Airforce models (Talon and Condor) and FX Verminator have the air bottle forming the buttstock, and this configuration lends itself very well to the high tech look and feel of their guns. The bottles hold a large volume of compressed air, and at full power can give up to 70 shots per fill. Dial the adjustable power down and you can get up to a couple hundred shots per fill! I find that with these bottle buttstock guns it is necessary to pay close attention to the scope mount used, if they are too high I find it difficult to achieve a consistent sight alignment. However, with a medium profile mount I do very well with both the Talon and the Condor. Airforce also sells spare tanks for back up, and even have versions that are purpose designed for different shooting situations (low power/low airflow versions for instance).
The method of filling these guns vary from manufacturer to manufacturer; in some models there is a filling port built into the gun so they can be refilled without demounting the bottle from the rifle. In others the bottle is removed and attached to the filling tank with a connector, filled, and then the full bottle is remounted. And in some there is the option to use either method, which is my preference. I like the option to carry a full tank that can be swapped for an empty in the field, but also like the option to quickly refill the gun without going through the extra steps of removing the bottle first. Regardless, the primary advantage of all of these guns is the increased shot count even when the gun is set for the highest possible power.
I like the bottle fed rifles when hunting in target rich areas. On a recent prairie dog shoot out west, where I got a couple hundred shots a day, the FX Royale 500 let me stay in the field for long periods. This was a great step saver, in that we were spot and stalk hunting and managed to move a couple of miles away from the truck on each outing. On more than one occasion I was still knocking prairie dogs over as we hiked back to the vehicles, while my buddies had long since run their guns dry. Between the high volume of the onboard bottle and the ability to carry a compact lightweight extra bottle, you don’t really need to stop shooting with these guns. That’s something to think about if you plan to do a lot of shooting!