First generation Auto-Ordnance Thompson Model 1927 manufactured by Colt Patent Firearms from 1927 to 1936. They were modified from original 15,000 Model 1921 Sub-Machineguns into a semi-automatic-only configuration. By removing the full-automatic rocker pivot assembly and converting the selector paddle into "single-fire" only position, allowing fire control assembly to be used as a semi-automatic only firearm. An estimated 50 such Model 1927 Semi-Automatic Carbines are believed to have been assembled and sold. Since these fire from an open bolt as the fully automatic Model 1921 and are (or can be readily converted to) full automatic, these first generation Model 1927 Thompson guns are considered to be machine guns by BATFE and must be transferred through a Class III dealer. Due to the scarcity of these firearms, a list of values would be very speculative. A base price of $35,000 is a good place to start. NOTE: Many thanks to George Layman for his assistance in contributing to this section. — Editor.