Yes. the older GI bore cleaner- US 30-06 was corrosive up into the early 50's.
Could I ask how you are cleaning barrels now? I shoot a lot of Commie 7.62 and Turk 8mm- For me, rifle goes in padded vise, muzzle down at a 45 degree angle, bucket under muzzle, plastic funnel in chamber. Quart of HOT water poured thru bbl, bronze bush with Dawn dish detergent, scrub bore 20 strokes, another quart of HOT water, 2 clean dry patches, wait 10 minutes, oily patch, wipe off and oil bolt, put away.