Gauging interest in an adjustable bolt

[GunsCarsPlanes]

I live behind enemy lines and currently do not own any transferable MGs

That's legit, you're really into this stuff wow. I come from MA where transferable MGs are allowed but you need to go through the C&R route then each and every firearm has to be approved by the police chief who can and almost always denies the request. You need to live in the middle of nowhere and have some sort of special connection with local PD.

Then I moved to IL where it's not possible whatsoever....so I moved to IN! I'm lucky though not many people can or would be willing to move like that in part for guns.

 

[MitchWerbellsGhost87]

Then I moved to IL where it's not possible whatsoever....so I moved to IN! I'm lucky though not many people can or would be willing to move like that in part for guns.

I wish I could relocate down south and get an FFL/SOT license, make my small gunbroker business into a genuine class 3 gun business, but I’m kinda stuck here, I own another business and it’s an industry in which I am licensed only in my state, and it would be a process to relocate and start over from scratch… so I live with the unconstitutional gun laws and regulations.. I try not to let them ruin the hobby for me, but no… no transferables for me at the moment.



Anyway to stay on topic, I see a few folks mentioning the idea of a slow fire M10 bolt. I know this has been mentioned before and there was a CFW m10 prototype. I imagine these would cost a fortune due to the amount of material required to manufacture a tungsten bolt for the M10. Probably a little easier to slow the M10 than the M11 since the M10 is already slower to begin with, especially the M10/9, but I can’t imagine any kind of “affordable” tungsten M10 bolt ever existing.

 

[SecondAmend]

...
Anyway to stay on topic, I see a few folks mentioning the idea of a slow fire M10 bolt. I know this has been mentioned before and there was a CFW m10 prototype. I imagine these would cost a fortune due to the amount of material required to manufacture a tungsten bolt for the M10. Probably a little easier to slow the M10 than the M11 since the M10 is already slower to begin with, especially the M10/9, but I can’t imagine any kind of “affordable” tungsten M10 bolt ever existing.

There was never any interest in a 9mm M10 tungsten bolt as the ROF was considered tractable with the OEM steel bolt. The prototype .45 ACP M10 bolt weighed 58 oz. As well as cost (which, IIRC, kept the "Interested" list at fewer than 30 individuals), there was a video showing the prototype being fired in full auto. The firearm (having about one-quarter of its total weight being the reciprocating mass) appeared to be difficult to control. The "bowling ball in a shoe box" effect that some shooters of direct blowback submachine guns with heavy bolts such as the M3/M3A1 find off putting.
MHO, YMMV, etc.

 

[GunsCarsPlanes]

prototype .45 ACP M10 bolt weighed 58 oz.....................having about one-quarter of its total weight being the reciprocating mass

That's bonkers....how the heck; 58 ounces!!!

 

[Galil#1]

There was never any interest in a 9mm M10 tungsten bolt as the ROF was considered tractable with the OEM steel bolt. The prototype .45 ACP M10 bolt weighed 58 oz. As well as cost (which, IIRC, kept the "Interested" list at fewer than 30 individuals), there was a video showing the prototype being fired in full auto. The firearm (having about one-quarter of its total weight being the reciprocating mass) appeared to be difficult to control. The "bowling ball in a shoe box" effect that some shooters of direct blowback submachine guns with heavy bolts such as the M3/M3A1 find off putting.
MHO, YMMV, etc.

WOW... also... 58 oz. would it have the "beat the shit out of your receiver" effect too? Extra heavy duty main spring needed?

 

[MitchWerbellsGhost87]

There was never any interest in a 9mm M10 tungsten bolt as the ROF was considered tractable with the OEM steel bolt. The prototype .45 ACP M10 bolt weighed 58 oz. As well as cost (which, IIRC, kept the "Interested" list at fewer than 30 individuals), there was a video showing the prototype being fired in full auto. The firearm (having about one-quarter of its total weight being the reciprocating mass) appeared to be difficult to control. The "bowling ball in a shoe box" effect that some shooters of direct blowback submachine guns with heavy bolts such as the M3/M3A1 find off putting.
MHO, YMMV, etc.

It sounds like this would have relatively quickly blown out the rear end of the gun. If it didn’t completely break it, it would at least bow it outwards a bit. Regardless of buffers or good TiG welds. The M11a1s were properly tig welded, but most attempts to run 9mm through them has resulted in blown out rear receiver ends.

I don’t know if the slower rate of the M11A1 CFW Bolt mitigates this issue, but I do know that it was a problem with the “MAXI” 9mm M11a1 conversion and I’ve heard it was also an issue with the SGW M11A1 9mm SMGs as well. These guns were welded properly (or should have been anyway) and I’m sure they had sufficient buffers installed.

This design just cannot handle the pounding at the rear end. There was a reason the “SLO-FIRE” RPB M10 was elongated so much at the rear end. It was ugly as hell and I’m sure the R&D guys at RPB tried literally everything to slow that gun down before settling for that fugly looking thing… but it was the only design that worked reliably and wouldn’t self destruct from pounding itself into oblivion. There is only one way to slow down the shorter frame without destroying the rear end, but it’s unreliable at best.

If you create some kind of drag on the bolt, it slows it down a bit. Autowerkes made a design years ago that looked reminiscent of a closed bolt semi auto hammer, spring loaded. I cannot recall if they made it for the M10 or the M11 or both, but it was installed behind the magwell inside the gun and it impeded upon the bolts rearward travel just enough to slow it down a tad.

I don’t know how well it worked, but I do know for a fact that a little drag can absolutely slow the gun down quite a bit.

 

[Offmarksman]

The M11a1 Cfw bolt does not hit the rear when shooting 9mm.

 

[MitchWerbellsGhost87]

The M11a1 Cfw bolt does not hit the rear when shooting 9mm.

I figured it was a non-issue with the M11A1 CFW, but those old school 9mm M11A1 attempts were not as successful, using modified versions of the original cast bolt with upgraded recoil springs. The MAXI configuration used a special double spring, and worked fine in semi auto apparently but would demolish guns in full auto. The SGW 9mm had a similar settup with a special spring, same problems. Sounds like no matter what is done with the spring, that old bolt just wasn’t heavy enough to prevent it from beating up the rear of the frame.

 

[Homer]

Gauging interest in an adjustable bolt​

• Thread startergorillastomp
• Start dateJan 24, 2024

[IMG alt="gorillastomp"]https://uzitalk.com/forums/data/avatars/m/9/9137.jpg?1693472325[/IMG]

gorillastomp​

UZI Talk Life Member

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• Jan 24, 2024
• 
  
• #1

Working on a project that would allow the rate of fire to be adjusted. This would be for all the Mac and M11 platforms.

Question. Is there any interest in such a product?

Back on topic...
Yes I will buy one for an swd m11/9.
cfw for m10 has been discussed in full for years.

 

[gorillastomp]

The idea is to slow the bolt without adding any extra weight to the bolt. It’s keeping the original weight or even lighter and being able to get your desired speed. If you like faster than stock that isn’t a problem.

This will be an ideal bolt for a ghost upper. Small compact slow and controlled.
We are in the process of machining parts now. One part had to be outsourced so it is taking a bit longer than expected (way it goes). It’s our first project so I expect many hiccups.

 

[strobro32]

I'm looking forward to seeing the design.

 

[MitchWerbellsGhost87]

The idea is to slow the bolt without adding any extra weight to the bolt. It’s keeping the original weight or even lighter and being able to get your desired speed. If you like faster than stock that isn’t a problem.

This will be an ideal bolt for a ghost upper. Small compact slow and controlled.
We are in the process of machining parts now. One part had to be outsourced so it is taking a bit longer than expected (way it goes). It’s our first project so I expect many hiccups.

The only thing I can think of that can accomplish this without adding weight would be creating some kind of drag on the bolt… or adjusting spring tension, but I don’t think spring tension alone would be enough to actually accomplish any kind of reliable rate reduction... can you give us a hint as to how this design works?

 

[strobro32]

The PM-63 RAK delayed slide works without lots of weight, drag or spring tension to lower ROF.

 

[MitchWerbellsGhost87]

The PM-63 RAK delayed slide works without lots of weight, drag or spring tension to lower ROF.

Yes but this is a totally different kind of action than an Ingram design, which doesn’t even have a slide. The skorpion uses a counter weight inside the grip too… there’s lots of different methods of rate reduction, but I’m talking about what’s possible with an Ingram using the OEM upper like OP has insinuated

The autowerkes rate reducer I mentioned previously is very similar to this polish SMG rate reducer.

 

[gorillastomp]

I'm looking forward to seeing the design.

I plan to use you as a beta tester. So you will get to see it hands on. If you are interested?

 

[gorillastomp]

The only thing I can think of that can accomplish this without adding weight would be creating some kind of drag on the bolt… or adjusting spring tension, but I don’t think spring tension alone would be enough to actually accomplish any kind of reliable rate reduction... can you give us a hint as to how this design works?

It’s not done with drag in the normal fashion. I can’t go into much detail. We are thinking outside the box on this one. All the models show it works. Give us a few more weeks.

 

[skoda]

The PM-63 RAK delayed slide works without lots of weight, drag or spring tension to lower ROF.

That is a really clever design!!!!!

GS; I too am looking forward to see your design concept.

 

[mwarnick1]

can you give us a hint as to how this design works?

I started typing out the same post but then figured I’d just have to wait to see 😀

Not using drag “in the normal fashion” is something interesting to think about

 

[Slowmo]

The PM-63 RAK delayed slide works without lots of weight, drag or spring tension to lower ROF.

It’s interesting that it delays the closing of the slide, not the opening. It would be interesting to try to reverse the mechanism to delay opening, but I suspect the opening impulse is too fleeting in duration to give the mechanism time to both engage and disengage.

 

[Homer]

I'm no where near an engineer or inventor but outside the box... somehow capture the blow back and have a controlled release of the pressure using it as a bleed off like in a hydrauic floor jack. If people will wait, I will show you how mine works.