I don't doubt that the SN range you referenced may be 100% correct for model-marked M50's (post 1958 production),Mentioned earlier in this thread was the model 50, Chiefs Special Target!
The model 50 was assigned in 1962 but never used in production until 1973.
The serial numbers know for the model 50s were all in the floating J system and were from 930Jxx thru 936Jxx. There were 1132 guns produced from 1973-1977.
jcelect