First of all, you must understand that something that you shoot with an air rifle will move so fast that it cannot be captured with the shutter speed of the camera. The only thing you can use to freeze your subject is light, flash light to be precise.
Flash light of the speed light is much faster than your shutter speed of your camera. You use two or three speedlights to be able to expose your subject well and you ensure that they go off at the right time, so that you get a nice action photo. As I said before you need to 'freeze' a popping balloon with a very short flash. I usually use 3 speedlights to illuminate the object. If you use the speedlight on the weakest power, the flash is the shortest and the photo will be sharp and no movement will be visible. Of course you also have the least amount of light so you have to experiment with the power of the speedlights, the aperture and the ISO to get the best results.