Getting Away

Gary Wain weighs up the technical factors involved in testing the heftier .22 pellets.

So far I’ve only been looking at the faster and lighter pellets that live at the sexy .177 end of the pellet scale. To even things up a bit, I thought that this month I’d turn our sights on .22 pellets, and in particular some of the heaviest pellets we could find to see what sort of damage they’ll do to the ballistic material. For this round of the testing, I selected a couple of hollow points around the 15gr mark, namely the Ultrashock HP which weighs in at 16.66gr, and the Dynamic XP2 which comes in at slightly lighter 14.5gr. To add to that, I’ll be following up with the 26.4gr Ultramag metal tip, and the heaviest pellet that I have looked at so far in the series, the aptly named H&N Piledriver which tips the scales at a whopping 30gr. From the start I want to acknowledge that these heavier pellets are primarily intended for FAC-power level air rifles, but that said, I wanted to see what sort of results I’d get when I popped them into sub 12 ft.lbs. rifles. Also, in order to establish a baseline I’ve used a 15.9gr domed Sovereign Rangemaster, and a 13.7gr flat-nosed JSB Jumbo Match

PHYSICS

First, let’s remember that I’ve been promising to look into, and to the best of my humble ability attempt to explain, some of the physics behind the testing I’ve been doing. In particular I’m going to look at a prickly little subject which goes by the name of ‘Ballistic Coefficient’, or BC for short. Now, for those of you who don’t like numbers and equations, don’t worry, neither do I, so there’ll be none of that malarkey here. All I’m going to do is run through which factors are used to form a ballistic coefficient, and what relevance the BC has to us when we’re selecting a pellet.

CONFUSING?