The Kel-Tec SUB-2000 is a great pistol caliber carbine that is inexpensive, fun, and reliable. Now in its second iteration, the Gen 2 has noticeable improvements over the Gen 1 models including molded Picatinny rails on the handguard, a new front sight, new receiver, improved stock, and overall better ergonomics. There are still many weak points in the weapon — mostly involving polymer where steel or aluminum would be best. Most fans can look past the flaws due to the price and overall reliability, but now they don’t have to settle unless they simply want to.

MCARBO is leading the charge on offering Kel-Tec SUB-2000 fans a wide variety of hardware upgrades to resolve structural, functional, and ergonomic issues with their carbines. On my own Gen 2 model, I implemented eight upgrades that have literally transformed my Sub 2000 into a like-new weapon that looks and performs to its maximum potential.

I was able to upgrade all components in this list (including the feed ramp polishing) within an hour or so with the tools included in the Pro Performance Trigger Job Bundle. Parts are compatible with Gen 1 and 2 models through the MCARBO website.

Stainless Steel Feed Ramp Upgrade – $32.95

One of the smallest but most important components to upgrade is the original polymer feed ramp. While durable, at extreme temperatures during a long-range day I would much rather have a stainless steel feed ramp. The photo below shows the difference between the original and an unpolished MCARBO feed ramp. Night and day difference. Once polished using the available polishing kit, it makes cleaning a breeze and it functions flawlessly. Best part? Not having to worry about melting it.

Kel-Tec Sub 2000 Stainless Steel Feed Ramp Upgrade

Rear Tactical Sight (Peep or Notch style) – $64.95

The problem with the original polymer sight isn’t that it is polymer. It is that it is way too short with a peephole that is too small.  The height of the original sight requires you to smash your face into an unnatural position on the bolt tube, and once set it becomes difficult to get a good sight picture because of the tiny peephole that would be more effective for longer distances than what makes sense for a pistol carbine.

MCARBO offers aluminum rear sights in a peep or notch style. The MCARBO peep has a much larger aperture and allows for quick target acquisition, and the notch sight gives a familiar pistol style option for shooters. If you prefer a combat-ready sight such as a red dot – the MCARBO sights can be lowered by a convenient thumb lever. This upgrade is an absolute must for anyone who has fought with the factory sight before.

Top 8 upgrades every Kel-Tec Sub 2000 owner needs: MCARBO parts review

Pro Performance Trigger Job Bundle (Flat or Curved trigger) – $139.95

Kel-Tec is not known for its match-grade triggers. In fact, they’re quite heavy (9-10lbs) with mushy flex. The image below illustrates the difference between Kel-Tec’s original curved trigger and the flat (my preference) MCARBO anodized aluminum trigger. The original has a lot of visible grooves and uncomfortable imperfections, while the MCARBO trigger looks and feels amazing with the trigger pull cut in half to about 5lbs. It is like butter.  Along with the included aluminum trigger guard, it is exponentially more comfortable than the original setup. A less-inclusive trigger parts kit is available on the MCARBO website along with individual components for sale.

Kel Tec Sub 2000 Aluminum Trigger Guard, Grip Pin Upgrade and Spring Kit.

The list of all 26 bundle components includes:

  • Hammer Spring
  • Sear Spring
  • Trigger Return Spring
  • Machined 6061 Aluminum Trigger
  • Machined 6061 Aluminum Trigger Guard
  • Set of 10 – Black Oxide Carbon Steel – 12.9 Class – Metric Screws
  • Set of 5 – Black Oxide Carbon Steel – Grip Pins
  • SUB-2000 Armorer’s Wrench – **Wrench fits Gen 2 Collar Only**
  • SUB-2000 Assembly Dowel
  • 2 – 2.5mm Allen Keys
  • Loctite 380 “Black Max” Plastic to Metal Instant Adhesive
  • Synthetic Grease w/ PTFE Teflon Lubricity

Extended Magazine Release (Glock or Multi-Mag) – $29.95

Another inconvenient component on the SUB-2000 is the small magazine release that often requires a shooter to break their grip to release and complete a mag-change. MCARBO’s solution is an extended magazine release that ensures it is accessible without breaking your grip. The larger release makes depressing it more effortless than the original. MCARBO offers it in a Multi-Mag option or Delrin Acetal constructed Glock option to prevent damage to polymer Glock mags. A seemingly minor upgrade until you actually do it and then you feel the difference.

Extended Magazine Release (Glock or Multi-Mag)

Bolt Tube Cover – $14.95

One of the worst aspects of the factory-original SUB-2000 for me was the uncomfortable cheek weld that I referenced earlier. I chose to look past it at first but now I don’t have to. Along with the raised MCARBO rear sight, the Bolt Tube Cover is a rubber sleeve that fits snug over the bolt tube and provides a surprising amount of shock resistance while adding much-needed height to your cheek weld. An added bonus is that it really improves the look of the weapon too. Cheap, easy to install, and well worth it.

Bolt Tube Cover

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Double Finger Extended Charging Handle – $29.95

The factory Kel-Tec charging handle doesn’t require super-human strength, but it is a bit stiff and requires a decent amount of effort to charge. It is meant for one-finger operation and just isn’t comfortable. I am perfectly fine accepting a little bit of comfort as long as it is functional too, and MCARBO’s charging handle options are a major improvement in both areas. I chose the double finger extended charging handle that allows a much better grip while not getting in the way even with the added length.

They also offer a heavier recoilless charging handle that is meant to reduce recoil by adding weight to the bolt’s action and slowing it down a bit. They also offer a skeletonized version of that same charging handle that is simply hollowed out to offer a better grip than the factory Kel-Tec option. One of the easiest upgrades to perform.

Top 8 upgrades every Kel-Tec Sub 2000 owner needs: MCARBO parts review

Single Point Sling Mount – $29.95

The Kel-Tec buttstock has slots meant for a sling, but I’ve never cared for that configuration and apparently, others don’t either because MCARBO offers a single point sling mount add-on. Very quick and easy to install and it does its intended job. Solid upgrade choice.

Top 8 upgrades every Kel-Tec Sub 2000 owner needs: MCARBO parts review
Single point sling mount.

Recoil Buffer -$9.95

The SUB-2000 doesn’t have a lot of recoil, but the buttstock tends to jump around a lot – particularly if you’ve got the .40 S&W model as I do. I’ve let others shoot mine and almost without exception that was their first observation. By adding this inexpensive Urethane rubber buffer, it offers a modest reduction in felt recoil, but when used with the MCARBO charging handles it becomes more significant. For less than ten dollars and seconds to install, it doesn’t make sense to not include this upgrade on your SUB-2000. This one is a no-brainer.

Top 8 upgrades every Kel-Tec Sub 2000 owner needs: MCARBO parts review
Kel-Tec Sub 2000 Recoil Buffer

Company president, Chris Nelson, is a former Special Forces operator and he personally offers fantastic instructional videos on the product pages to explain in detail how to perform each of these upgrades. Watch them and you can’t go wrong. I would recommend that you perform trigger, spring, and pin upgrades at the same time to avoid having to repeatedly take the lower receiver apart. MCARBO has identified virtually every issue with the Kel-Tec SUB-2000 and offered a strong solution. This is a result of them listening to their customer base for years as they developed these products based on the feedback they received. A company like that is going to have a loyal base, and I am included in that group. I look forward to seeing what they come up with next.

At the range, my post-upgrade SUB-2000 didn’t even seem like the same gun. Prior experiences with my SUB-2000 were like a forced marriage – I wanted it to work but I just wasn’t happy. MCARBO changed that with their upgrade products and I can’t recommend them enough to other SUB-2000 fans. It went from a fun but uncomfortable weapon to one of my favorites to shoot. Check out their site and start getting your upgrades planned.

Top 8 upgrades every Kel-Tec Sub 2000 owner needs: MCARBO parts review
Author at the range with his Kel-Tec Sub 2000 and Ammo-Inc Streak non-incendiary tracer rounds

*All photos courtesy of the author

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