Virtually all top shooters use either hardened stainless steel or carbon fiber rods.
Virtually no top shooter will use a brass or especially aluminum rod.
This is counterintuitive.
You'd think that a softer rod would potentially do less damage to a muzzle or bore.
However, soft metals allow grit to embed into the metal and that can turn a cleaning rod into an abrasive lapping rod.
The hard stainless will not embed grit and just wipes clean.
Even worse are the screw-together rods. They never mate up perfectly and the sharp edge where the rods join can really ruin a muzzle or even chamber.
One trick to limit potentially damaging a barrel is to PULL the rod.
This prevents the rod from flexing and bumping the bore.
Even with rifles I can clean from the chamber end I still pull the rod through by putting it through, screwing the brush or patch and patch holder on and pulling it out the chamber end.