Top MCARBO Kel-Tec Sub-2000 Rifle Upgrades

After owning the Kel-Tec Sub-2000 for some years, I wanted to fully customize the gun to fit me, and only one company had what I really needed: MCARBO. That’s because MCARBO has a long history of making custom precision components for a myriad of different firearms. Everything from relatively inexpensive guns like the Kel-Tec Sub-2000, all the way up to pricy carry pistols like the SIG P365.

So, what are these must-have MCARBO Kel-Tec Sub-2000 Rifle upgrades? Let’s find out.

The MCARBO optics mount is rock-solid and easy to install. IMG Jim Grant

KEL-TEC SUB-2000 Optic Mount

The biggest shortfall of the Sub-2000, in my opinion, is how optics can’t be mounted on the gun if a shooter wants to retain the gun’s folding capability. Some companies have made mounts like the pivoting one from Midwest Industries, but I found that MCARBO’s solution is much more elegant.

MCARBO action
The Kel-Tec Sub-2000 is a vastly more usable carbine with the addition of an optic. IMG Jim Grant

Their mount replaces the first four bolts on the handguard and utilizes the existing nuts to mount the optic as close as possible to the shooter. But the most brilliant part about the mount is that fact with its spring-loaded. So all a shooter has to do is press a single button, and the mount conveniently flips 90 degrees to the left, allowing the gun to fold in half.

The MCARBO extended magazine release is well-made and effective. IMG Jim Grant

MCARBO Extended Magazine Release

One area of the Sub-2000’s design that I personally didn’t think needed improvement was the gun’s magazine release. But after installing the new one from MCARBO, I really can appreciate the difference. On the stock design, if a shooter has smaller hands, they’ll have to rotate their firing grip partially around the grip to reach the release. The MCARBO one, however, makes it so all but the smallest shooters can reach the release with ease – making reloads much faster and improving the gun’s handling and potential weapon retention (since a shooter can retain their natural grip on the gun).

MCARBO trigger guard
The replacement trigger guard is built like a tank! IMG Jim Grant

Improved Aluminum Trigger Guard

While this might seem like a fairly boring upgrade, it actually makes a lot of sense for shooters who intend to put their Sub-2000 through some serious hard use. That’s because, unlike the original factory latch, the MCARBO version is built from heavy-duty aircraft aluminum. This means that it both will be smoother in operation and be much more resilient to breaking or damage.

MCARBO folded
Check out how the MCARBO folds out of the way with a push of a button. IMG Jim Grant

Aluminum Trigger and Trigger Bar

Last but certainly not least, the engineers at MCARBO designed a trigger replacement that swaps out both the trigger and its bar – because the Sub-2000 is a bullpup, after all. And it makes a world of difference in the trigger pull. In testing, the stock trigger broke at about six and a half pounds. After installing the MCARBO setup, my Lyman trigger scale measured it at around four pounds. This makes accurate fire and follow-up shots much, much easier.

MCARBO folded iron sights
One cool feature of the MCARBO optics mount is how it can fold away if the optic should fail, letting shooters use their iron sights. IMG Jim Grant

Another benefit of the trigger is its shorter, crisper reset. Where the factory trigger on the Kel-Tec is certainly serviceable, the break and reset can feel a little spongy. That all goes away with the MCARBO parts. I’m not certain how they accomplish this, but I assume it’s because they use more rigid components. Regardless of how it’s done, the improvement is undeniable.

About Jim Grant

Jim is one of the elite editors for, who in addition to his mastery of prose, can wield a camera with expert finesse. He loves anything and everything guns but holds firearms from the Cold War in a special place in his heart.

When he’s not reviewing guns or shooting for fun and competition, Jim can be found hiking and hunting with his wife Kimberly, their son, and their dog Peanut in the South Carolina low country.

Jim Grant