That makes as much sense as trying to put a square rock in a round hole. I think you have a whole lot more research to do. Don't get me wrong, There is some truth to what you are saying, despite saying some things completely wrong (as if my barrel changes shape from a long cylinder to a square). But it is clear that you are trying to regurgitate what you have read elsewhere, but don't fully understand.
I know, I can't just say that without backing it up. So here is a cursory effort as I have more important things to attend to at the moment.
"Each round equals more friction, and explosion"
My guess is that you mean that as a bullet travels down the barrel and the bullet engages the riffling, there is friction between the bullet and barrel. The friction creates heat. A portion of the heat is transferred to the barrel, and continued shots without allowing the barrel to cool raised the transferred heat, thus increasing the temperature of the barrel. As metal is heated (in this case the barrel) it expands (but how much heat does that actually take), in the barrel's case, potentially making the barrel inside diameter slightly larger. The difference could be insignificant or significant, either making the rifle less or more accurate based on individual rifle differences, bullet selection...
":Explosion" = a violent or destructive shattering of... Explosion does not equate to the controlled rapid expansion of gas created as the powder in the case is exposed to a spark or flame created from the firing pin striking the primer of the cartridge. I think what you are getting at here is that the burning of powder that creates the rapid controlled expansion of gasses is a heat producing event which in turn transfers heat to the barrel.
In short, the point you appear to be missing is that this process and it's affects are exactly the same, proportional to the volume and density of the barrel given the same metal type and quality and density.
So to sum this up, THERE IS NO DIFFERENCE.
However, knowing Form (@
Formidilosus), I will not be surprised if he provides examples from his experiences comparing and contrasting barrels with literally THOUSANDS of rounds through each.