At this point in the war Federal cavalry was well armed with breechloading weapons and obsolescent muzzleloading weapons would have been of little use to them. Also, Grierson's Raid was a fast moving mission. They had neither the time nor ability to gather captured material and carry it off. The carbines were just a small part of material destroyed at Verona. There are too many different reports of the destruction there to contemplate that it somehow didn't happen.
Russ Pritchard