Looks like a Sarco hand select basement special

Yeah, looks kinda like they pulled it out of the Channel a couple years after D-Day, doesn't it?

Just for the record.
Its not really a good idea to turn an open bolt gun into a closed bolt blowback, especially if your bolt is of the same weight as the regular open bolt.
The reason for this is that open bolt guns do have a lock, of sorts: Differential lock by advanced primer ignition.
For subguns, this means that the round fires BEFORE battery ( can explain ).
This results in the bolt having an effective weight of more than its mass due to its forward inertia.
And no, a stronger spring will not work really.
This is why closed bolt blowbacks usually shake themselves to bits.

You got to remember though the firing pin “nub” is ground off and a hole is drilled through the bolt and a “real firing pin” is attached/utilized. Also, especially with Sten builds, the new semi auto receiver is usually a reduced diameter so a lighter (ground down/lathed/turned)bolt is used so the bolt is lighter than the original.

I had a Soumi semi auto that started life as a open bolt blowback full auto. I put a lot of rounds through her and it did not appear to want to shake apart.

Well, shake itself to bits...relatively speaking.
If you compare it to an open bolt gun, you will get my drift.
Try it out and you will see.
The reason why the general perception is that it does not matter much is that open bolt guns are not that common.
All the closed bolt-blowback guns I tried, Famae, Specter, Skorpion, sten, sterling have this sharp recoil that open bolts dont.

The few locked breach , pistol cal carbines- MP5, MPX , just about get away with it, but still not as smooth shooting as an open bolt.

After numerous trials and experiments with various designs, I dont think that its a question of "manning up" to the recoil.
The best virtue of a subgun is its versatility:
At 0 to 10 M, the ability to engage multiple targets of opportunity; And, deliberate fire, in semi or controlled bursts, up to 100M or more.
The only other gun that comes close is the shotgun, but not really, because at cqb ranges, its a one hole gun, plus its recoil does not permit accurate burst delivery.

A subgun is effective at very close ranges because it is easily controllable due to very low or non existent recoil.
Even carbine calibers are not really suited for this role.

I had to mention the intended role, as reference to the original inception and purpose of the weapon.
All that said, one CAN certainly build a closed bolt , blowback , pistol caliber carbine, even with reduced bolt weight, but at a cost. So maybe as a range toy its ok ( and i have plenty of those :-) )

Nope, stronger spring will not make it better (much).
Mass and accelleration matter, and all a stronger spring does is transfer recoil force to frame.

quote:

Originally posted by schatzperson:

I had to mention the intended role, as reference to the original inception and purpose of the weapon.

Sorry. Not to take away from the very astute observations regarding original design objectives regarding sub machine guns....

However, like captain says “what we got here is failure to communicate”....

See, here In the People’s Democratic Republic of Freely Elected Representative Democratic Freedom of Equality Super Democratic Extra Free Comfie Zone State of Seattle (and bits of equally retarded King County and you had best just forget the rest of the entire state that has actual jobs and stuff you retrograde reactionary running dog imperialist bastards!)

Nope. Here The whole point isn’t that you have a piece of history. You know when normal good people won out against fascist bastards.

Nope. Nor do you have a piece of workmanship that is interesting from an engineering standpoint regarding efficient manufacturing in a time of hardship.

No. No.... you just have an “extra eeeeeevvil super extra assaulty murder machine killy thing weapon of mass extreme shootie death stuff”.

Probably with a shoulder thing that goes up you bastard!

Bill R
(Prolly shouldn’t post after watching local news with bourbon)

Easy on the bourbon Sty !
But I feel your indignation.
Not partial to alcohol, so I deal with it by being as objective as I can.
So we cant have little guns with no recoil to pepper goons at bedroom ranges...hmmm
Wonder, if a Calico pistol could do as a replacement. Come now, 100 rounds of no4 buck size heeled 22 cal
bullets cant be that bad.
You know, one of these days, someone is going to come up with a nice, affordable, 9mm carbine, closed bolt and smooth as silk, with a 100 rd mag that always works.