By the way, I did lay all my M-10's out together tonight. I have seven of the so-called 1912 version with the turned down bolts. Interestingly, four have 28 inch barrels and three have 26 inch barrels. Length of pull varies from about 13 and 3/8 to 13 and 5/8. Most are in the 9xxx serial number range but a couple are a fair bit higher numbered. I have kept every turned down bolt variation I have acquired over the years.