Well…….. I have a pre May Sten. It now shows transferable. I did a “Test” efile form 4 transfer and it allowed me to add it. I canceled it of course. It’s showed “Orange” before. Now it’s white!!! What theeeeeeeee Fuuuuuuuuuuu……..
If your referring to what does the rear of a m10/m11 upper rests on it’s this. #27. Full auto guns use the rear stock block. The semis use #27.
https://www.ftfindustries.com/category/M11PS.html
Here is a better option of the rail you provided imho. Smaller foot print.
https://www.usmachinegun.com/proddetail.php?prod=M11SA-RRMN
Or this
https://macmachineguns.com/?product=picatinny-rail-stock-adapter-semi-auto-m11-9-or-m11a1-380
For full auto guns this is a better option as well if...
So I guess to answer your Orginal question I think and just my two cents it’s bulky and blocky. There are better options out there that if using this semi auto set up don’t look as “Blocky” imho. YMMV. Ty
I haven’t read the website. The gun in the pic you provided is A SEMI AUTO MAC!!! look at the safety selector. Will it fit a FA mac? Not sure it looks like the adapter has two holes on the bottom so possibly!
Good luck. All the the “Complete” parts kits are gone. Haven’t seen one with the firing pin included in one in years! Most of the kits have the fixed firing pin as well.