M*CARBO Brotherhood

Sub2k +P ammo fix

All Things SUB-2000!

Newbie here. have sub2k gen 2 with mcarbo upgrades. trigger kit etc…
Like the concept except the +P issue. Maybe brainstorm ideas for mcarbo fix. My idea is a thin metal plate of similar material to aluminum trigger guard that would wrap around upper to lower interface. This seems to be the point of greatest stress. Thoughts ?

I probably don’t get it, but, ???

I don’t understand what or why?

Problem with +P in a blowback action is going to surround issues with accelerating and decelerating the bolt. The brass bolt extension is the best available way to mitigate accelerating wear from violent starts and stops, but it really isn’t a fix.

You are going to be fine shooting a few +P unless your luck’s already run out.


Welcome to the forum samiam. There is an introduction thread but I am too lazy to link to it.

Thanks for the input. ordered kel tec brass bolt. Been shooting standard pressure 9mm rounds ( 115 and 147 gr) Goal is to be able to shoot +P pressure also. Maybe one +P for every 15 standard pressure.

The higher chamber pressure is a concern, too. The biggest one, IMO. You’d need a whole new barrel to safely handle a steady diet of +p.

Thats my concern as well. Seems like you can shoot some +P . Wondering where the line is. The sub2k 40 guys seem to be able the hotter loads in essentially the same gun as the sub2k 9mm. Standard pressure is 35000 psi… +P is 37000 psi. Can’t find any data on what the commercials loads actually run. Have all the mcarbo upgrades with exception of muzzle brake. Think keltec heavy bolt will help but wonder if will cycle standard loads properly. Gun works fine now.

The new NATO 147 grain runs about 36500 psi I believe