wasn't going to jump in but l will give my opinion
of course a boresnake can damage a rifle bore, you could never get all the grit from cleaning a bore out of the fibres in the snake
so you are pulling the grit over at least the muzzle but if the boresnake fits the bore you are pulling the crud over the bore as well
boresnakes are so old school its funny they are still around, they keep the salesman happy
they were good when there was nothing else in the days that we cleaned our rifles with boiling water and old sump oil
there is a better way to clean your rifle bores so why clean your bore with sh!t
reallywould you clean the outside of your rifle with the cruddy cloth you just cleaned your brushes with
of course you wouldn't and even without the grit a rope will wear down steel, have a real good think about it
use a good quality 1 piece coated or carbon fiber cleaning rod and quality brushes, you will get years out of it
just some common sense really 