Here’s an interesting video, well narrated.
I am good with a pistol. Very Good, in fact. I focused on pistol proficiency while preparing informally, and in later formal training for my second trip to Afghanistan. I decided that my “most likely use case” was being surprised at short range in close quarters, and prepared myself accordingly. I drilled twice daily throughout my deployment, in a self-designed regimen, which included a fairly obsessive clearing and checking practice.
Anyway, I neglected my long-arm skills as much as I could. I declined the opportunity to carry both guns. The rifle would only get in my way in most scenarios, and given the real need to carry two types of ammunition just to support the burden of carrying two types of weapon, the option to carry the rifle “just in case” is not cost-free. To the contrary, I decided that the cost outweighed the benefit, given that a rifle fight probably meant more of a fight, and that in such a circumstance, I would not be hard-pressed to find a newly-available rifle.
Well, the rifle at my option was a carbine anyway, and it took me some time to learn why it was called a carbine. Turns out that there are two distinct reasons for calling a rifle a carbine, which I learned from the comment of this video, and upon consideration, it has the ring of truth.
There is a sphoisticated argumrnt for the ideal barrel length based on pressure and mass, and therefore velocity, as well as accuracy, but these wind up being secondary considerations in real-world military situations. What really matters is the ability to launch lead downrange effectively and swiftly, which has a lot more human factors than the ideal calculations will reveal.
Of note, as he discusses in the last use case, the Colonnier (sp?) is every morsel the length of a long rifle, but take a moment and look at the greatly reduced furniture (the wood, more or less). Despite the lack of a length distinction, that Colonnier is a much nicer rifle to carry and operate just by the sight of it.