A 'STEN' type 9mm submachine gun which fires from an open-bolt and uses 1.5" Steel Round Tube combined with a 3D printed lower receiver. The lower receiver can accept either printed or surplus STEN magazines. The SMG is constructed in much the same way as the MK1 with the exception of an extended receiver tube with a perforated shroud section incorporated.


#### Receiver Tube:

38.1mm x 1.6mm Wall Steel Round Tube (1.5" X 0.065 wall). 445mm in length.


#### Bolt:

35mm (1 3/8") Mild Steel Round Bar. Can be 'machined' using an angle grinder and drill press.


#### Recoil Spring:

                  
Compression spring taken from a lever type grease applicator gun.


#### Sear:


The sear is cut from 10mm thick steel plate and is retained (via a 6mm dia pin) in a housing welded to the Upper        Receiver Tube. The trigger is printed and is retained in the lower receiver via an m6 bolt or pin.



#### Barrel:


The barrel can either be turned on a lathe as a single piece or assembled from 3/4" Steel Shaft Collars and 3/4" tubing. The barrel is fitted into the receiver tube by drilling several holes through the receiver and plug welding in place.

 3/4" Imperial Shaft Collar: Inside Diameter: 075 inch Outside Diamter: 1.375 inch

Refer to ‘Project-ButWhatAbout: DIY Electrochemical Machining a 9x19mm Rifled Barrel’ by IvanTheTroll.

#### Magazine:

DIY STEN magazines (DB Alloy / DannyMeatball)
- *Original surplus STEN mags require a printed insert.