Owning a Kel-Tec Sub 2000 Gen 2 means you have a compact, folding pistol caliber carbine that's fun to shoot, but it's not without mechanical quirks. If your carbine experiences failures to feed, stiff charging handles, or rough triggers, you aren't the only one. These issues usually stem from tight tolerances, a heavy blowback design, or polymer wear points.
This guide breaks down the most frequent Kel-Tec Sub 2000 Gen 2 problems and gives you concrete, actionable solutions to fix them. You'll learn how to diagnose cycling failures, correct heavy trigger pulls, and maintain the folding mechanism so your carbine runs reliably through every range session.
Failure to Feed and Chamber Issues
A failure to feed (FTF) happens when a cartridge strips from the magazine but jams against the feed ramp or fails to enter the chamber completely. On the Sub 2000 Gen 2, this is frequently caused by magazine compatibility, a dirty chamber, or wear on the polymer feed ramp.
The factory magazines and grips vary wildly depending on whether you bought the Glock 19, Glock 17, Smith & Wesson, or multi-mag version. Aftermarket or worn-out magazines often have weak springs that fail to push rounds up fast enough for the fast-cycling bolt.
How to Fix Feeding Failures
- Check and swap magazines: Test a factory OEM magazine to rule out feed-lip deformation or weak follower springs common in cheap aftermarket mags.
- Inspect the feed ramp: The Gen 2 features a polymer feed ramp integrated into the lower housing. Over time, aggressive round feeding or improper cleaning can chip or mar this surface. If it's heavily grooved, replace it with an upgraded stainless steel aftermarket feed ramp.
- Scrub the chamber: Blowback firearms throw carbon straight back into the action. A dirty chamber restricts cartridge seating. Use a chamber brush with solvent to remove stubborn carbon rings.
Failure to Eject and Extraction Failures
Failures to eject (FTE) or stovepipes occur when the spent casing doesn't clear the ejection port, trapping it between the bolt and the chamber. Because the Sub 2000 relies on a straight blowback operation, it requires crisp extraction and consistent ammunition energy to cycle properly.
If you shoot underpowered target loads or cheap steel-cased ammunition, the bolt might short-stroke. Furthermore, carbon buildup around the small claw extractor can prevent it from biting securely onto the rim of the casing.
How to Fix Ejection Issues
- Clean the extractor claw: Remove the bolt assembly during a standard field strip and use a pick or nylon brush to clear carbon buildup out of the extractor hook.
- Upgrade your ammo choice: Switch from light, underpowered 115-grain reloads to standard pressure 124-grain factory loads to ensure the bolt gets pushed all the way to the rear.
- Inspect the ejector: Ensure the fixed metal ejector inside the receiver is not bent, loose, or chipped.
Heavy, Gritty Trigger Pull
Out of the box, the Sub 2000 Gen 2 trigger is notoriously heavy, stiff, and gritty. Because the trigger linkage runs through a long plastic housing back to the hammer, you deal with significant flex and friction.
While you shouldn't expect a match-grade 2-pound break from a folding backpack carbine, the factory setup can cause finger fatigue during high-volume range days.
How to Improve the Trigger
- Perform a clean and polish: Disassemble the lower receiver and polish the metal sear and hammer contact points using fine-grit polishing compound. Never alter the actual engagement angles, as this creates a dangerous drop-fire hazard.
- Install an aftermarket trigger kit: Many owners replace the factory plastic trigger and internal springs with aftermarket drop-in kits from manufacturers like MCARBO. This reduces pull weight significantly and removes the mushy wall.
Folding Mechanism Binding and Latch Wear
The defining feature of the Sub 2000 is its ability to fold in half, but the hinge and locking latch can get sticky, stiff, or loose depending on maintenance and environmental exposure. Dirt, sand, and pocket lint easily find their way into the pivot points when stored in backpacks or vehicle trunks.
How to Maintain the Hinge
- Keep the pivot clean: Use compressed air and a solvent-soaked brush to clear out debris from the rotating barrel assembly hinge.
- Lubricate sparingly: Apply a drop of lightweight gun oil to the pivot pins. Avoid heavy greases that attract dirt and turn into an abrasive paste inside the polymer housing.
- Check the locking collar: Ensure the rotating forend collar locks tightly against the receiver. A loose collar introduces play into the barrel, which directly ruins your zero.
Accuracy and Sighting Shifts
Some shooters complain about poor grouping or wandering zero with the Sub 2000. Because the front sight is mounted on the rotating barrel assembly and the rear sight is fixed to the polymer receiver, any tiny amount of play in the hinge lock-up translates to noticeable shifts downrange.
How to Tighten Your Groups
- Adjust the front sight properly: The Gen 2 uses an adjustable AR-style front sight post. Make sure it is screwed down tightly and not wobbling in its base.
- Watch out for heavy optics: Mounting heavy red dots or scopes directly to the factory handguard requires specialized folding mounts. If you mount an optic incorrectly, it will lose zero every time you fold the carbine.
- Read the manual for safety and specs: For official breakdown diagrams and maintenance guidelines straight from the manufacturer, consult the Kel-Tec Support Center.
Frequently Asked Questions
Can I shoot +P ammunition through a Kel-Tec Sub 2000 Gen 2?
Kel-Tec rates the Sub 2000 Gen 2 for standard pressure SAAMI-spec 9mm ammunition. While it can handle occasional +P rounds due to its robust steel bolt and polymer shell, heavy a steady diet of +P will accelerate wear on internal polymer buffers and springs.
Why is the charging handle so stiff to pull back?
The straight blowback design requires a heavy recoil spring to keep the breech closed safely until chamber pressures drop. Breaking it in over a few hundred rounds, or adding an aftermarket charging handle sleeve, makes gripping and pulling it much easier on your fingers.
How often should I clean the Sub 2000 barrel?
Clean the bore every 300 to 500 rounds, or immediately if you shoot corrosive surplus ammunition. Always run your cleaning rod from the chamber end toward the muzzle to avoid damaging the crown.
Is it normal for the polymer frame to show slight seam lines?
Yes. The receiver is constructed from Zytel glass-filled polymer, and minor mold seam lines are completely normal factory characteristics that do not affect structural integrity or performance.
