The H&R HAMMERLESS shot gun was offered from 1925 to 1941, in two variation series. The "conventional" letter code dating system will only work for the last two years of production - earlier pieces can have year of manufacture estimated by serial number. (i.e. need s/n posted)
This model was unique in the H&R line-up. It featured a "military type" spring mounted striker with very short lock time and was advertised a being useful for Trap shooting as well as hunting. It was at the top of their price chart and furnished with a "better" grade of wood.