Did you ever measure them to check he wasn't bsing you?
I find it very hard to believe he talked to the machinist and that they were willing or able to do that.
Most guys operating those CNC machines wouldn't necessarily be capable of changing the program, nor necessarily the authority to do it.
Most front are actually machined from a stock which is very close to 0.7 size. So having a length of stock that could be machined to a smaller bore would take lots of work and money and contacts.
Possible, but I'd need to measure the barrel or know the guy has major contacts to believe it
manike