Frequently Asked Questions

What does NFA mean?

NFA stands for National Firearms Act of 1934 and it regulates short-barrel rifles (SBR), full autos, suppressed guns, and other weapons. If you buy an MCK with a stock, it’s an NFA item.

What is the difference between and NFA/Stock and the Extended Stabilizer?

The MCK with an NFA/Stock falls under the NFA classification (see above clarification on explanation of NFA). The MCK Extended Stabilizer keeps the pistol classified as a pistol per the ruling Bureau of Alcohol, Tobacco and Firearms (ATF)

I see the Micro Conversion Kit (MCK) on your website.  What is the difference between the MCK and the Micro Roni®?

We’ve improved our past generation models and created a new generation made 100% Made in the USA -we call it the Micro Conversion Kit, MCK!

Some of the additional advantages of the MCK, include:

  • One model fits more than one handgun
  • Charging handle stays inside of the conversion kit – making it one of the fastest pistol insertions and removal
  • Exposed slide release
  • Ergonomic front handgrip
  • Spare Magazine Holder
  • Comes with Extended Stabilizer Brace
  • Substantially reduced retail price – costing $100 less than the Micro Roni
  • 100% Made in the USA
  • Dramatically improves accuracy up to 200 yards
  • Available in 7 colors: Black, OD Green, Tan, White, Tungsten Gray, Pink, and our USA Patriot Flag

This new Micro Conversion Kit (MCK) is a lightweight, yet sturdy platform, that is currently available in 4 models:

  • Glock 17/19/19x/22/23/31/32/45 (Gen 3, 4, 5)
  • Glock 20/21
  • Sig Sauer 320 (Full Size and Compact)
  • S&W M&P 1.0 and 2.0 (Full Size and Compact)

Does the MCK fit generation 1 or 2 Glock® pistols?

No, the Micro Conversion Kits (MCK) only fits Generation 3, 4, 5 Glock® pistols. It is not compatible with generation 1 & 2 Glocks.

What Glock® pistols does the MCK / Micro Roni fit?

The Micro Roni® 17 ONLY fits Glock® models 17, 22, & 31 (generation 3 & 4). The Micro Roni® 19 ONLY fits Glock® models 19, 23, & 32 (generation 3 & 4). This also goes for the Advanced, Stabilizer, & Recon versions of the Micro Roni.

Whereas, the MCK fits all the models listed above in one chassis.

If I buy the MCK Stabilizer, can I shoulder it?

Our MCK Extended Stabilizer is designed as an arm stabilizing brace to offer support while shooting our platform.

See ATF Letter for more clarification https://www.sigsauer.com/press-releases/atf-clarifies-ruling-pistol-stabilizing-braces/

Do I get free shipping on the items I order?

Free shipping is offered on orders over $150. (Excludes all orders to Alaska, Puerto Rico, and Hawaii). For those in Alaska, Puerto Rico and Hawaii, you will receive free shipping if the total amount of your order equals over $300.

If I place an online order from the CAA website, can I come pick it up at your location?

Although we are an online-retailer/distributor-based company, we welcome you to pick up your order as long as you make an appointment ahead of time so we can properly prepare your order. Please call customer service to do so.

I want to buy an Extended Magazine or Drum Magazine from CAA USA. Am I allowed?

Yes we offer high capacity magazines for our MCK, however, the following states and counties are not allowed to own any High Capacity Magazines: California; Colorado; Connecticut; DC (District of Columbia); Hawaii; Aurora, Chicago, Franklin Park, Oak Park, & Riverdale, Illinois; Maryland; Massachusetts; New Jersey; New York.

Do you ship to California, New York, and New Jersey?

Yes, we do ship to California, New York, and New Jersey the Non-NFA products. It’s up to the buyer to research their state and local laws, as they may change frequently.

How long does it take to ship out my order?

We strive to process within 48 hours, however, there are instances where it can take longer to fulfill orders. Once your package is shipped, you will receive a shipped confirmation via email. From that point, it typically takes 3-8 business days to ship to your shipping address.

If I want to return my order, what is the procedure?

If you want to return your order, please go to the SHIPPING & RETURNS page and follow the directions there.

Are there any plans for additional MCK models?

Coming soon, are models from the following manufacturers:

Springfield Armory



Please visit our website or social media to stay up to date on the latest release and details.




Does the MCK work with Compensated Glock Models?

With the combination of the Aluminum Top Picatinny Rail on our MCK, compensated Glock Models such as the Glock 17C/19C/21C, and 31C are now compatible inside MCK Conversion Kit.

Does the MCK work with firearms that have a manual safety?

Our MCK does not work with handguns that have an external manual safety.

Does the MCK work with aftermarket sights on the handgun?

Stock sights always work best, however, the MCK works with aftermarket sights as well, as long as they are not suppressor height sights. Sights should be 0.4 inches or lower.


I’m experiencing malfunctions with my firearm inside the unit, what could it be?

If you were to experience problems with malfunctions such as Failure to Eject (Stovepipe), it could be one of a few factors.

  1. Please always ensure that your handgun is seated correctly into the charging handle. There should not be any serrations on the charging handle that are not aligned with the serrations of your firearm. Typically, seating the firearm all the way to the rear serrations of the charging handle will ensure proper fit.
  2. If you’ve done this and are still experiencing problems and have an optic on the MCK, remove the optic to dissect the issue. We have seen ejecting brace hit the base of some optics if the optic is mounted directly over the ejection port. This can be corrected by moving the optic further out on the picatinny rail or closer to the shooter.
  3. Please always ensure that when sliding the firearm into the MCK, the firearm is not pushed forward and locked at an angle. The handgun should stay level and straight as you push it forward to lock on the picatinny rail lock inside the unit.

If none of the above are a solution, please call one of our Sales Reps or Customer service so that they can walk you through a solution via phone and/or email.

I purchased a DRUM mag for my Glock, and I am having trouble with function, what can I do?

The manufacturer of our Drum magazines, RWB, has requested that we direct any questions or concerns about the product to him directly so that he can better assist you. Please find his information below:

Young K. Leigh, Ph.D., President of RWB



What is the difference between Gen 1 and Gen 2 ?

1. The Gen 2 MCK features a new extended stabilizer which allows the user to fire the Gen 2 MCK in the folded and locked position. The new stabilizer is compatible with Gen 1 MCKs as well.
2. The Gen 2 rear door extends back an additional 15 degrees, making it easier to insert and extract the handgun.
3. The Gen 2 MCK accommodates suppressor height sights.
4. The Gen 2 MCK features a new charging handle which makes more surface contact with the rear of the handgun slide.
5. The Gen 2 MCK features an aluminum top picatinny rail for improved stability, durability, and accuracy.
6. The Gen 2 MCK accepts CAA USA’s new brass catcher, made especially for our latest generation MCK. (Sold separately)
7. The Gen 2 MCK features an improved spare magazine holder that operates with a mag catch and magazine release button.
8. The Gen 2 MCK is suppressor friendly and can accommodate a suppressor up to 1.38” diameter.

For questions related to cleaning your MCK  click here

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