When comparing my two 1920's M&P's I notice that the earlier one (429908) has a top barrel address of 2-3/4 inch length whereas the later one (581864) has an address of 2-1/4 inch length. Anyone know when the change took place? Thanks, Ron
Sounds like you have narrowed it down with your serial numbers from the mid to late 1920s. I do not have any M&Ps that new, but I assume you are seeing five patent dates on 429XXX and three on 581XXX? Also, depending on the barrel length, there were either two or three lines in that same era. Neal/Jinks book states that late issues of 38 M&P, 4th Change revolvers have the last three patent dates only.
You are correct.....the earlier one has 5 patent dates and the later one has 3 patent dates. Both are 5 inchers. I am assuming that the change must have taken place sometime in the mid-1920's since my two M&P's date from ca.1923 and ca.1927 respectively. Ron
429908 probably shipped in 1922 or 1923 (more likely 1923) while 581864 probably would have shipped around mid-1928, but possibly later. Some probably have lists showing different patent numbering stampings for different times and serial numbers, but I have not seen one. I assume that when various patents expired, they were dropped from the barrel stampings. After WWII, they stopped stamping patents on the barrels.
I notice on page 235 of Neal and Jinks that in June, 1926 there was an order to begin stamping hammer and trigger with patent information. I am wondering if the barrel markings were also changed at this time as well. What think ye?
Barrel address size for 1920's M&P
Linear Mode
