Specialized Sten Barrels

[Brit plumber]

All production Sten barrels were of the same diameter stock, the Mk2 and Mk5 guns had the barrel bushes pinned in place. Machine time was the main cost in wartime and minimising waste. To machine a Mk2 or Mk5 bushing and barrel as one would take longer than separately. A good lathe could knock out lots of bushes in one pass, i.e. maybe 5 items at the same time.

I don’t personally believe Mk3 barrels were ever used as Mk5 barrels as I’ve never seen a Mk5 barrel with the short step breech end bushed. I would have to measure the bayonet lug end to see if it’s even possible. The Mk1 barrel appears to be identical to the Mk3 and it would make sense seeing as Lines simplified the Mk1 gun into the Mk3.

The standard Mk2 S guns used a shorter barrel which was more in keeping with the Mk1/3 style with reduced diameter shoulders at either end. If you see a Mk2 S suppressor unit breech end with the same fitting as the regular barrel nut then suspect it to be a replica. The correct unit has an extra section for the barrel to fit into.