M*CARBO Brotherhood

Limited Production: 80% Sub2K Lower

Would anyone be interested in doing their own sub 2000 build from scratch? I think it would be a lot of fun to do a complete build kit and video how to for a custom sub any way you want it. Glock or Multi Mag, 9mm or 40cal.
What are your thoughts on an 80% Bolt Tube for your own custom sub 2000 build? Is it still difficult to find a Glock 9 mm sub? This also might be a way to eliminate some of the difficulty in finding the perfect platform to start with.


Neat concept! Any ideas on what finishing steps would be required on the bolt/recoil tube?


It would be as simple as possible preferably. No special tools other than drill bits and a jig.


@ChrisNelson As long as it has the ability with a .30 caliber clip to disperse 30 magazine clips within half a second, I’m there, man!


Nearly everyting is available from KEL-TEC at the moment. https://www.keltecweapons.com/rifles/sub-2000#catalog

Not sure what it would add up to piece one together.


Kel-Tec parts? MCARBO parts! :+1:

But, yes, I know everything like the hammer/sear aren’t available as MCARBO parts…yet?

Also, how hard would it be to source the same grade of metal tube? Does Kel-Tec even release engineering info like that?

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We have the abilty to test it and figure out what material it is. Likely we would go above and beyond just to be safe on material selection.


Nice! I wouldn’t expect anything less. :smiley:


I was just thinking about it today as I was planning the new all in one video.

I was thinking it would be cool to just build a SUB-2000 from a bunch of parts rather than swaping out all of them we just start with a box of parts and assemble our own SUB-2000 that’s not traceable…:sunglasses:

I know it was mentioned once before in here.

Really want to pick the idea apart.


@ChrisNelson different calibers?

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And, no heat treatment/recall issues with the barrels, please! :rofl:


Possbily after we see how the “Limited Production” goes.

For now we could just use all of the Factory components on top of what M*CARBO already makes.

Basically instead of buying a SUB to throw half of it away we will just piece it together the way we all want it.

For instance KEL TEC sells the upgraded Brass Heavy Weight bolt for $45 which is just a little more than the $27 standard bolt. I rather just go right for the heavy weight bolt which I’m a big fan of. When using the Heavy Weight Bolt, with the M*CARBO Muzzle Brake, Recoil Buffer and Recoilless Charging Handle I had nearly zero felt recoil and muzzle flip.

Just build it as an M*CARBO SUB2K from the get go.


@ChrisNelson just spitballing, but what about performance accuracy barrels for production models currently?


Absolutely down the road. If we plan to change calibers we would need a different barrel anyway.

A .45 ACP SUB-2000 would need a new barrel and bolt and reciever tube.

We can see how a Limited Production 80% Lower Build goes for 9mm and .40 cal. If enought want a .45 ACP we can run the numbers and see if it makes any sense.


@ChrisNelson the wait is instantly killing me! :weary:


I just checked the parts list again and KEL TEC removed the barrels from the list. Possibly due to the recall?

I remember seeing them before and it was an available option to buy them at one time.

Now that throws a wrench into the idea.

Ultimately the goal was to use what was avaiable for the time being to make a 1,000 Custom SUB-2000’s from scratch just like an https://www.80percentarms.com/ or https://www.polymer80.com/

Are there any other 80 Lower Platforms out there?


I’m sure KEL-TEC would eventually get wind of it and say something…but no need to worry about that until it happens. Would be a good starting point for a future collaboration together once the marketplace has cleary supported the idea…how could they say “NO”.


If you get to .45, you can also get 10mm. 10mm is currently a growth Caliber, but it is not the first time 0 has been on a growth cycle. willit last this time?

And, I’m spitballing the 80% but alloy grip halves and an alloy forend with your optic mount or just a flip to side top rail would get me scraping together my coins.


I may have missed this. How would you handle serial numbers to keep BATF happy. Other than this point I am onboard with this build. R S


@RodSlinger 80% lowers are not firearms and do not need to be serialized. They are considered gun parts and can be shipped directly to your house without FFL requirements. Colloquially referred to as a “ghost gun”. Not illegal to build your own gun for personal use.