No serious discussion on rifles can be conducted unless we examine bore diameter as it relates to the practical rifle If we accept as a given that the purpose of the practical rifle is simply to deliver a bullt to a target than we must consider the bullet. The gun writers that preceded us liked certain calibers and extolled their virtues. For example, we remember that Jack O'Connor liked the .270 Winchester, Elmer Keith liked the big bores, and Jeff Cooper was fond of the .30 calibers. Each of these esteemed writers had their arguments and their reasoning. It is not for me to disagree with them. However, one of the biggest differences we have these days is with the quality of the bullet available. These esteemed gentlemen simply didn't have the bullets we have today.
While it's true that size matters, I don't believe that it matters as much today as it did in earlier days. Today's rifleman has a wide variety of bullets to choose from, suited to particular tasks, regardless of the game. Whether paper, steel, or hunting, there are bullets suited to the task and it is our happy task to choose the right bullet for the job. If we're considering the practical rifle, then we must ask the question' Practical for what? There's the rub.
The practical rifle should be suited for the task at hand, and different riflemen need different rifles. A hunter going afield for brown bear in Alaska should probably carry a larger bore than the hunter down south who wants to take a whitetail deer. We understand the difference between dangerous game and herbivores, and we understand the difference between the woodlands of the East, the thickets of the South and the vast areas of open land out West.
With the better bullets available to us, I believe that we can step down one caliber from what the old-timers considered suitable. So, when considering the practical rifle and we consider caliber, the simple answer should be that the caliber be sufficient for the task that the rifleman might be expected to encounter. I know that this is not an entirely satisfying answer, but it is the one that we are left with and should provide plenty of fodder for the campfire discussions.
Note, for the record, that I consider the humble .22LR to be America's favorite cartridge, and I do not include the rimfire in the discussion of the practical rifle. It is my firm opinion that every rifleman should have at least one rifle chambered in .22 Long Rifle and should use it frequently. As a small game rifle, as a training rifle, as a practice rifle, the .22 should be considered a mainstay of every battery.