Hey guys! September from Bullberry here.
We have no record of this odd stamping or special caliber, because of its age. However, even during that era we were willing to custom-stamp barrels at a customer's request. Quite a few barrels have left the shop with custom caliber designation in the past (typically using a pet name or the customer's name). On a more modern barrel we would be sure to engrave both the unique designation AND the true caliber (probably under the forearm or on the bottom of the underlug).
As with all of our products, if you need assistance from us or are interested in finding out more about it by having one of us check it out in house, simply send it in. We don't charge for stuff like that, so you would only have the expense of shipping.
I would probably recommend refinishing the barrel if you send it in, to include a new engraving with the appropriate caliber designation. This is a $50 charge typically, but in this case where clarity is an issue we can reduce that expense to $25. The barrel would likely be in house for up to 2 weeks depending on when our next bluing was scheduled.
I apologize for not having gotten in contact with you sooner. We received an email today that referenced your GBO thread, so I figured this would be the best method of contact. We are a small production facility and the phone is regularly busy. If you would like to call us, please make sure to do so from 8am-noon or 1pm-5pm Mon-Fri, Mountain time.
I don't have a fax from you, though Jean thought she remembered reading something about this caliber question. Again, apologies for the lack of communication, particularly if we did receive a fax and misplaced it.
-September @ BB
435.635.9866
