If the bore snake erodes the crown, then the chamber leade will also wear.I wouldn't, they make 7mm (.270) bore snakes that would be better suited. The .30 caliber brush is going to be really tight in that bore and may run a risk of eroding the crown with excessive use. Besides, patches will clean the bore properly themselves.
I had used brushes, and bore snakes in the past, but honestly I find it to be overkill. I've seen rifles that were extremely dirty, with deposits all over the crown, that shot sub-MOA shot after shot.Sorry to go a bit off-track here, but are you recommending not using brushes in general? I use brass brushes for cleaning all my rifled gun barrels...just wondering if I shouldn't be.