Hello
I also have a 1928 Browning 22 Trombone. Based on the serial number given, your gun dates prior to 1956 because it has no prefix or date code. Therfore based on total product of about 150000 units over 53 years your rifle should be a late 1940's model. I would say some ware around 1948 - 1949.
Hope this helps.
Mark
You must call Browning. The sn does not follow conventional numbering.
1922-1968. You will have to get it lettered by Browning to narrow it down further
Mine is SN. 234xx. What year mfg. Tks .
Need the sn to answer
1925
91748