Bore brushes?

[KnifeLicker3000]

Iosso

 

[mikerotchburns619]

It can hurt. Make sure you use bore guides and a good rod. I’d guess more barrels are ruined by the break in process than helped over crappy cleaning practices and supplies.

Two douche responses with no help to the OP’s question. I know you have learned a lot about guns while playing call of duty but leave the real advice to people who build and shoot real guns.