Thread: Redundant Calibres

Originally Posted by Micky Duck

..there are three parts to it... how fast bullet is being driven, how fast its being spun and how hard/stout/soft/fragile the make up of bullet/projectile itself

@Micky Duck, You're overthinking that a little - the only real part to it is the end part and then matching the bullet to the velocity required and the terminal performance needed. Then the bit about selecting the twist rate to stabilise and making sure the entire package is feasible and obtainable i.e. barrels in the required twist rate.

Example there is using a .22Hornet rabbit bullet in a high speed .22 centerfire is going to produce interesting results, explosive is one potential word. On the other hand, a .220 Swift varmint bullet makes a handy penetrating bullet in a .22Hornet, good for slipping into the neck/head of fallow and goats. Both barrels seem to run similar twist rates, the only real difference is horsepower behind the pill. The other 'fourth factor' missing from your list is barrel length, which governs how fast you can drive the pills everything else being equal.