system
Given the following post, respond as if you're commenting on Reddit:
human
[Halo] Are there canonical reasons for the Plasma Rifle being called a "rifle" & its very low projectile speed being considered practical/worthwhile by the Covenant?

Been curious about this for a good bit. Thank you!
gpt
Well, it's not a pistol, is it?  
Obviously the traditional concept of rifling doesn't apply to plasma weapons, but the general parlance of weapons being divided into handguns, rifles, and what not is still convenient.  
So while the plasma rifle isn't actually a rifle in the technical sense, calling it such makes it easy for troops to understand where it fits in the order of battle.  
Projectile speed is intrinsic to the weapon design, and isn't actually considered to be that slow by Covenant standards, given that they haven't seen a high-velocity chemical propelled slug for many thousands of years.  Even then, such technology is considered primitive and unworthy, despite projectile velocity.