My grandma used to say "Johnnie, if it's accurate, don't fuck with it."
JCN

No, muzzle blast.
High expansion ratio + RL 15, so there shouldn't be any problem doing it. If I ever get around to building a 375 or 416 Taylor or 416/376 Steyr for Alaska bear backup while fishing I would probably go with a 21" barrel.
It's easier to cut metal off than to weld it back on so think about this for a little while at least. Does your gun balance OK as it is? Do you envision using 350 grain bullets for plains game, elk, or moose out to 250-300 yards/meters? Is your rifle accurate as is?
I suggest putting at least two hundred rounds (jacketed and cast) through it before you get out the hacksaw. I had the same inclination when I got my 416 Rem in 1990 (or thereabouts, I can't remember details any more). I waited for a year and then decided that I liked the balance and the longer sighting plane for the iron sights more than I wanted to chop and channel my rifle.
But, if you want to do it go for it. If it doesn't work out you can always put a Krieger tube on it. That would make it easier to clean at least.
JCN