40x
Rod,
The above answers are correct. But if you want to know for sure look at the serial number on the receiver. If it has no letter suffix it is a 40x, (1955 to 1963). If it has a letter "B" as a suffix to the serial it is a 40XB, (1963 to 1972). If it has a letter "R" as a suffix it is a 40XR (1972 to ).
The reference to 722 vs 700 is in the letter suffix or lack there of.
These are two good pic's showing how the "XB" tang was slightly slimmed down from that of the "X".
Mad,
No, neither all nor most civilian actions are 40X. Over 22,000 of the 40X were produced.
40XB's were again more than 22,000 produced. serial numbers run
consecutively.
bjm