I think your M-38 shipped in 1982. But that's a guess based on assumptions.
haywood
It is a "floating J" but it is not from 1982. The OP figured it out correctly in Post #3 - 1972.
Here is the rule of thumb to keep these straight:
In the "floating J" years (1971-72) there will be a total of no more than 5 numeric digits. Some will be before the J, some after.
When you get to the 1982-83 period, there will always be 6 numeric digits in the serial number.
haywood
It is a "floating J" but it is not from 1982. The OP figured it out correctly in Post #3 - 1972.
Here is the rule of thumb to keep these straight:
In the "floating J" years (1971-72) there will be a total of no more than 5 numeric digits. Some will be before the J, some after.
When you get to the 1982-83 period, there will always be 6 numeric digits in the serial number.