STEN Mk İ semi-auto 9mm carbine Build Project. \r \r This is a legal semi-auto build and an approved STEN design by the ATF. The STEN was built to comply with both Federal and State firearms laws.\r \r STEN Mk İ parts kit looks to have been built originally in the 1st half of 1944 according to the serial #. Its a Finnish Army model (stamped [SA]), which included a sling swivel under the receiver and on the stock.\r \r The reduced diameter STEN tube will not accept the original STEN FA Open Bolt. The unfinished STEN tube, semi-auto bolt, 16 barrel, a recoil assembly is from Indianapolis Ordnance.\r \r Most of the drilling and machining was done on an old 1hp Rockwell drill press. I purchased a cross slide table (X & Y axis) and a vise. Used some center point drill bits and a couple end mills. Dremel, angle die grinder, cut-off tool, aircraft rivet gun, hand files.\r \r Special features:\r Removable barrel and front trunnion.\r Lower receiver lug, allow the complete removal of the trigger group.\r \r Finish:\r Parts blasted with aluminum oxide, then Parkerized with Manganese phosphate solution, and painted with Dupli-Color Engine Enamel semi-gloss black (#DE1635).