Q: I have noticed that some air rifles are now available in really big calibres, with pellets weighing 50 grains or more. Though my current preference is for .177, I’m intrigued to know the benefits of the larger calibres.

A: Bigger, heavier pellets tend to be designed for use in FAC-rated airguns, producing muzzle energy from 30ft/lb to more than 100ft/lb. Their increased stability, especially at high velocity, helps to improve accuracy. They also hit really hard, delivering high levels of shock energy, which is a prime concern when targeting live quarry. If you are using a legal limit, sub-12ft/lb airgun, I would suggest that .177 or .22 calibre is the way to go, though the larger .25 can be useful for close-range pest control.