Sten ejector design

[StrangeRanger]

On the Mk 1 Sten the ejector was simply an extension of the inside leg of the mag catch retainer.  On the subsequent marks the ejector was a more complex piece inconveniently welded to the inside of the receiver tube.  The only reason that I can see for replacing a simple readily replaceable part with a more complex one that is not field serviceable is that the simple one didn't work.

I can envision three failure modes:

1. The Mk 1 ejector broke off in service
2. The Mk 1 ejector was not far enough forward to guarantee reliable ejection
3. The Mk 1 ejector was too far forward to reliably maintain in contact with the ejector slot in the bolt when at full recoil
4. Some combination of the above

Are there any other failure modes that I have overlooked?  Does anyone know with absolute certainty why the design change was made?

Edited May 24, 2024 by StrangeRanger
spelllling

[APEXgunparts]

The STEN Mark1 ejector sounds like the same part used in the STEN Mark III.
The Mark 2 and Mark 5 both have the welded in part.
The Lanchester uses a machined part that seems to appear again in the Sterling.

Richard

[StrangeRanger]

Richard,

I've never seen a Mk 1 or a Mk 3 in the flesh but I saw the Mk 1 in Ian's current video on Forgotten Weapons and it got me wondering about the change from the Mk 1 design to the Mk 2.

Your input makes it even more puzzling.  If the original design worked well enough to resurrect it for the Mk 3, why did they change it on the Mk 2....and why did they change it again for the Mk 5?

"Inquiring minds want to know." 🤣

Mike

[BillyDixon]

with the welded in place ejector on the MK 2 sten you can rotate the mag housing, this was done for compact packing on the oss parachute drops to behind the lines, just sayn

[StrangeRanger]

That makes sense but the welded extractor had to add significant cost to the Mk 2. Since they wrung every other shilling out of the cost I have to wonder why they kept it on the most widely produced version of the Sten rather than restricting it to a limited model issued just to Commandos, Paras and the Maquis