Is it necessary? Maybe not...but...I was taught by a CMP Hi-Power Trophy winner how to clean and break in a match barrel and I've been doing the regimen ever since. Why take the chance? Clean and Prep and clean after range sessions is part of the process. I know a lot of guys that don't even clean barrels between range sessions. Not I. I agree with DanB. You'll be surprised as to how dirty new barrels are, and initial cleaning can reveal dirt and burrs. Myself? I start with pristine barrels, but that's just me. Is it necessary? I don't know another way. What's Ernie have to say on this one? He needs to reap the most accuracy for long range groups.