"Firing from an open bolt"

[cowart]

Pretty much all machine guns are open bolt aren't they?

The Heckler & Koch MP-5 is a conspicuous exception

 

[Gryffydd]

The Heckler & Koch MP-5 is a conspicuous exception

Except isn't it technically not a machine gun?
*As in small arms classifications, not government regulations.

 

[Deanimator]

Except isn't it technically not a machine gun?
*As in small arms classifications, not government regulations.

No, it's a machinegun by any reasonable definition. It fires two or more consecutive rounds with a single pull of the trigger, whether it's full-auto or (n) round burst.

Submachineguns are just a sub-category of machineguns.

 

[Deanimator]

The Heckler & Koch MP-5 is a conspicuous exception

A lot of early rifle caliber and larger machinegun designs fired from a closed bolt, including the Maxim, Vickers, Schwarzlose, Revelli, Browning M1917/M1919, Browning .50 (M1921/M2), etc.

 

[pryd4tsmg]

Speaking of lock time & Thompsons, a couple friends and I spent an afternoon on the leavee utilizing the rear sight to it's max extent. All the fields were tilled, and impacts showed up really well. I was curious to see how well it would shoot out to 600 yds. and beyond, and was surprised how accurately it could hit. Lock time was lousy, but you could compensate for it when you got used to it. Full Auto at that range was laughable. But for single shots with the sight elevated as high as it would go, we could have made an enemy soldier pretty nervous. Raise gun, fire, lower gun, wait for impact. (Now read that real slow and you get the idea.)
Had a boss who wanted to shoot it, and at thirty feet and 20 rounds, didn't even hit his hardhat. Same gun, different shootist. But I do love the Family Thompson!

 

[Avenger29]

Some may be wondering "Why use an open bolt design"?

Well, not only is it very simple to manufacture, but it helps with cooling, too. You don't want a round cooking off in a hot chamber.

 

[ACP230]

Folks with good reflexes can fire single shots from some subguns you wouldn't think would allow it.
My son can even fire singles from a PPSH.

I can do it from a Swedish "K" for the first hour of a shooting session.
After that I get tired and two and three round bursts is what I get when I try to shoot "short."

Last time I fired a Reising M50, .45 ACP closed bolt subgun, I got one single shot with the gun set on FA. I think that's the first time I've been able to do that.

 

[Hk91-762mm]

The original UZIs were open bolt ,,I bought a cut up one hoping to make a semi auto out of it-- Too Much work,
Same with the port Said I got =Muffler pipe with a fixed fireing pin bolt on a spring.. I have seen the STEN guns --same thing
PPHS Chi-com Is an open bolt too...
Funny-you should heve seen me trying to remove the fireing pin from the Port Said - Yeaa I can laugh now !!

 

[Deanimator]

Same with the port Said I got =Muffler pipe with a fixed fireing pin bolt on a spring..

The Port Said's just a copy of the Carl Gustav (Swedish K).

 

[Sunray]

"...sure the Thompson SMG was a closed bolt design..." Nope.
"...all machine guns are open bolt aren't they?..." Nope.
"...technically not a machine gun?..." Nope. Sub-machinegun.
"...dust cover has a bracket that..." The dust cover was/is also the safety.

 

[Wile E Coyote]

Add to the open-bolt design the ole M-60 that I lugged around for a spell in the early 1990's. That one was easy enough to single fire. Heck, even expected to do so during a portion of certain range qualifications.

 

[graywolfls]

Just a side note. I have a Demro 45 cal open bolt semi. It is a delight to shoot, uses grease gun mags and even as a semi auto it fires so fast most people think its a full auto. Its got a lock built in (combo /sesame type) And the words THINK in bright red on the rear of the receiver, Gives one pause before you send a 45 cal stream of bullets down the range. To the best of my knowledge this is one of the very limited open bolt semis out there, but they do show up every now and then.

 

[justashooter in pa]

Open bolt sub guns gained favour in the years following the First War. Their design was refined over the the next 3-4 decades in the interest of enhanced reliability, reduced cost, simplified manufacture, and reduced weight, until they fell out of favour in the 60's. A good example of the development sequence is the Beretta design series. Guns in this series from the 20's and 30's were complicated and required hundreds of machining steps. They reached a peak of complexity in the 1938 model (which was well regarded), which had a floating firing pin that was levered into action by a pivot as the bolt came home on a cartridge. By '42 the floating firing pin had been replaced with a fixed pin, and excess weight like the barrel shroud and compensator were gone, as well. the 1951 model was a stripped down 42/43 with a wire stock ala grease gun, but never really caught much attention. Procurement was already looking to get out of machined receivers, entirely, and to replace pistol cartridges with "intermediate" cartridges like the 8X33/762X39/etc.

 

[Deanimator]

Add to the open-bolt design the ole M-60 that I lugged around for a spell in the early 1990's. That one was easy enough to single fire. Heck, even expected to do so during a portion of certain range qualifications.

A lot of gas operated guns fire from the open bolt. That's why they weren't popular as synchronized aircraft guns. The lock time was long enough to make precise synchronization very difficult. On the other hand, they made good flexible guns, the Lewis, Vickers "K", and ShKas being examples.

 

[Voerelover]

Try the openbolt voere mod. 2005 smg in .22lr you can write your name on a pine board! fires about 600 rds being a .22 recoil is just not a problem I picked two guns back in 1988 at Atlanta SWD. Hard to find now but they are still around, and it is no doubt the cheapest Mg openbolt gun around and add loads of fun!