Wolfgang, I"ll leave the particulars on the .445SM to those that have em, like I said, I don't have one, just passing info that has been shared here. One of our members, DRinks, recently rented a reamer from 4D, other than that, most did theirs last year sometime and as Digger said, they were all happy with the results. If I were to find a bargain barrel, I'd probably buy it and ream it myself, I've throated 2 Handis so far, the hand rechamber doesn't sound much more difficult from everyone's report.
Tim