Hi guys,
There are several ways to address the barrel/arbor fit. Weld up the end of the arbor, fine it back. Center bore the arbor, fit a Dillon cartridge locator pin, file it back. Center bore the arbor, tap the hole for a machine screw, file the screw head back. These fixes should require the removal and replace of the arbor, which em tales drilling out the retaining pin and either driving in a new pin or drill and tap the hole for a small set screw. All of the foregoing can get expensive if your not flush with so e skill and precision tools. Some time back, I discovered stainless 5mm split washers at Lowe's. I told the whole world about it at the time and I think some thought I was nutz for using such a back yard fix. I found dropping the split washer down the barrel bore for the arbor and reassembling the gun fixed 99.99 percent of ASM guns and 99 percent of Uberti guns. At a cost of about .08 cents per gun. Just remember to put the washer back after cleaning.
Whew....... This has been the wordy version of Yes. If the gun was found to need the arbor fix (it will) I'd tell him about the little split washer to fix it.
Coffinmaker