Cleaning rods...
Smokin' Iron--ANY cleaning rod MAY pick up crud. The crud MAY then be hard on the bore with the next pass of rod through bore. I understand that burnt particles from primers are actually a sort of ceramic, and much harder than steel. Burnt or unburnt powder, soot, bullet lube, leading, copper fouling, and plastic residue in shotgun bbls, aren't hard enough to damage steel.
BTW, bullets of lead or copper alloy, aren't hard enough to damage steel either.
Segmented rods have the joints between segments, as crud-catchers. Brass rods are soft so hard bits of crud may become embedded in the brass. Likewise plastic-coated rods for that matter. Steel rods are relatively hard and will normally not become embedded with crud, but being steel they are relatively hard, and can thus wear on the bbl all by themselves.
It's an individual choice.
For me, I avoid segmented rods altogether--except for my emergency rod, which takes down and fits in my range box and therefore is never left at home, and gets used about once every 10 years but is a godsend when I need it.
I also avoid steel rods for their hardness--except the above-mentioned emergency rod which happens to be steel. But it gets used so seldom that it hardly counts.
Military rifles get cleaned, and cleaned, and cleaned, and the rods are often steel, and no provision made to keep the steel off the rifle bore. And many soldiers, while courageous fighters, are not primarily gun-minded--they just want the bore mirror-bright so Sarge doesn't dock them on inspection. That's where you encounter the most cleaning-rod-caused bore damage.
I used to use brass rods, but that was before I quit using segmented rods as a regular thing.
The rifle rods I normally use now are one-piece Dewey plastic-coated rods. And I wipe 'em off after every pass through the bore. The coating is dark; you can see any particles that might be stuck to the rod. The coated rod itself, clean, won't hurt the bore.
(Nothing magic about Dewey, BTW, but that's the brand carried by my LGS. Any other coated one-piece rod would be the same IMHO.)
With a rod considerably smaller than the bore (e.g. when cleaning a .50 cal. BP rifle, or a shotgun) a rod guide in the muzzle will keep the rod off the bore. With a bolt rifle, a rod guide that replaces the bolt, and inserts into the chamber, is a great help, but the rod is so similar to the bore that I'm sure there is contact between the 2 regardless. The chamber rod guide does serve to keep solvents out of the rifle receiver, so it's a good thing for that reason.
Anyhow, bottom line: It's up to you, and there are pros and cons to be balanced no matter which way you decide.
