I've been given a 0.22" cal. Relum Tornado to clean the barrel. On inspection it seems to have a smooth-bore barrel. Is that so or is the rifling on this one so bunged-up with crud, I can't see the rifling. I've always been told not to use a phosphor-bronze brush on rifled airgun barrels but if it is a smooth-bore, it would be okay to do so ... or what? Thanks in advance for any/all replies. Regards ... Geek