Why was the Montreal Home Guard's Model 99D called a "musket"? What makes a fairly modern, breech loaded, centerfire rifle a "musket" when the term refers to a muzzle loaded smooth bore? Why not carbine? Just curious.

The word "musket" in the 19th century was used to describe any long barreled full-stocked long arm intended for military use, be it smoothbored, rifled, muzzle loading, or breech loading. You're right though, one would think that the term would have become archaic by WWI. I suspect that the old farts who got the honor of naming military hardware were all products of the early-mid 1800's and simply didn't go along with the young crowd. Remember that the Civil War was still fresh in everybody's minds at the turn of the century- it was a shorter time span than the years we today are seperated from the end of the Vietnam War. A guy in his 50'-60's (like many of us here are) with his brand new M1899 in hand in the deer woods of 1900 could've easily been a Civil War veteran.

I have in my possession a British infantry manual dated 1915 titled "The Rules of Musketry" which is a dandy treatise on the nomenclature, maintenance, and marksmanship with, the Enfield No.1MkIII rifle, and the small unit infantry tactics decreed for the users of same. Fascinating reading. It was intended for use by non-coms and field grade officers to teach Tommies how to shoot Gerries, and not get shot themselves.

That makes sense. The word just conjured up images of a blunderbuss type weapon in the hands of musketeers. Hah!
So the carbine would be the opposite of the musket then, being short barreled?
The Enfield in its various forms is another one of my interests.

The 1899F carbine (saddle ring carbine) had a 20" barrel and the same buttstock more or less as the musket. I'm sure Savage promoted it as a military arm also.

Another thought relates to how the militaries of the world viewed riflery 100+ years ago. Even though individual marksmanship was honed, by and large, rifle fire was assumed to be directed against mass formations of enemy troops. As such, volley fire was still taught. High volumes of aimed accurate fire put down on tightly packed bodies of troops was pretty effective. (Witness that such gunfire is what basically saved the BEF in Belgium, September 1914. The British Regulars then depended on rifle fire more than machine gun fire.) Single-mindedness of commanders who clung to archaic open ground battle tactics providing such lush targets for riflemen and machine gunners (and artillery) was the primary cause for the horrific casualties in The Great War. High volume fire (musketry) was pretty effective against high volume stupidity.

The "Mad Minute" is another interesting part of musketry and Enfield history.

1895 carbines were going to be sold as part of the army and NY military trials if they had been won and followed through on, as well as the muskets.

The "Mad Minute" is another interesting component in the history of musketry practices and the Enfield.