Semi-Only Sten Concept Design (click here to download as a PDF file. then select save)

NOTE: This design has not been reviewed by the BATF and is offered as a "Concept" on a way to approach a semi-auto build. Remember, any build must meet NFA/BATF guidelines.

You would also need to mill the feed lips on the bolt flush with the cartridge face.

Here's my logic as to why this would be a legal design...

1. Even though this is an original  ID receiver, the new hammer assembly and rail will prevent the installation of a F/A bolt.
2. The lower, with the modifications for the AR trigger group and rail, would not allow the original F/A fire control group to be installed.

Why I think this would be a good working design...

1. No tricky slide hammers
2. No special small diameter springs to compress/ fail
3. Proven reliable AR trigger group
4. Uses Original Sten spring
5. Bolt will be approx. only 1.5" longer than the original for good travel and function with the spring.
6. Modified Bolt will be the tried and true Sten bolt on the business end.
7. Original ID allows use of original trunions and spring cap.

I recommend fitting your AR trigger group to the lower Before building the extension to verify your bolt requirements.

**Note: This design would require that the "width" of the AR fcg be adjusted to fit housing. Also, overall hammer height would need to be reduced.

Drawing is easier to read in the "PDF" format....

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