• There are few quick things to review if you’re having trouble fitting your pistol in your MCK:
  • Aftermarket parts such as threaded barrels, sights, back straps, frame alterations can alter your pistol’s footprint and cause binding or mis-alignment.
  • Double check pistol compatibility. Be sure your handgun matches your MCK model and the handgun model is stamped on the inside left wall of your MCK. 
  • Adjust your barrel shroud to be sure it is the correct position for your compact or full size firearm. The ship is configured for compact pistols, so it will not seat properly if you try to fit a full size handgun without adjusting the barrel shroud. 
  • Insertion technique is critical to ensure the frame rail of your pistol aligns with the rails inside your MCK. Line up the grooves and smoothly push the pistol forward until it clicks into place. Watch the official step-by-step demonstration here: Proper MX1 & EVO Insertion Technique Video. 

Troubleshooting MCK Fitment: What to Do When Your Pistol Won’t Lock In

Unboxing a new Micro Conversion Kit (MCK) is exciting—until you try to slide your handgun in and hit an unexpected wall. If your pistol feels stuck, won’t lock into place, or doesn’t seem to fit at all, don’t worry! In most cases, this comes down to a quick adjustment, an aftermarket part clearance issue, or a slight tweak in your insertion angle.

Follow this troubleshooting guide to get your pistol locked in, loaded, and ready for action.

1. Beware of Aftermarket Parts

Before tweaking your kit, take a close look at your firearm. While the MCK is engineered to fit factory handgun specs precisely, aftermarket modifications can alter your pistol’s footprint.

The following custom additions are common culprits for fitment issues:

• Threaded Barrels (can add extra length or require shroud adjustments)
• Night Sights & Suppressor-Height Sights (may catch on internal channels)
• Aftermarket Backstraps & Beavertails/Dovetails (can alter the grip angle and thickness)

Pro Tip: If your handgun features any of these modifications, keep reading—you may just need to adjust your shroud or tweak your loading technique.

2. Verify Your MCK Compatibility

It might sound obvious, but always double-check that your handgun matches your specific MCK model.

All MCK units are stamped directly on the inside left wall with the exact handgun models they are engineered to support.

1. Open or unlock your MCK chassis.
2. Look at the inside left wall.
3. Confirm that your specific handgun make and model are listed on the stamp.

3. Adjust Your Barrel Shroud (Compact vs. Full-Size)

Many MCK models are designed to accommodate both compact and full-size handgun variants.

By default, MCK units ship configured for compact pistols. If you are attempting to insert a full-size handgun into a default setup, it won’t seat properly until you adjust the barrel shroud.

• For Full-Size Handguns: You must extend the internal barrel shroud forward into the “Full” position.
• Watch the Guide: Check out this quick tutorial on How to Adjust Your MCK Barrel Shroud.

Special Instructions for MCK 2.0 & MCK 3.0 (Threaded Barrels)

If you are running an MCK 2.0 or 3.0 with a threaded barrel, standard fitment settings change slightly:

• Compact Handgun + Threaded Barrel: Extend the barrel shroud forward to the Full-Size position.
• Full-Size Handgun + Threaded Barrel: Completely remove the shroud assembly from the MCK.

4. Master the Standard Insertion Technique

Angle matters! Pushing your pistol straight in at a flat angle can cause the side grooves of your slide to catch against the internal frame rather than seating cleanly.

The Fix:

1. When inserting your pistol, tilt the barrel ever so slightly downward.
2. Line up the side grooves on your slide with the alignment mounds inside the MCK chassis.
3. Smoothly push the pistol forward and home until it securely clicks into place.

5. Loading Instructions for MX1 and EVO Models

If you own an MX1 or EVO model, loading requires a specific angle and motion sequence to bypass the internal tension system properly.

Follow these steps to ensure smooth insertion:

1. Insert & Retract: Insert your pistol into the chassis, then pull the pistol back as far as it will go inside the EVO/MX1.
2. Tilt Down: Tilt the barrel downward until the front of your pistol rests against the bottom interior surface.
3. Push Forward: Maintaining that exact downward angle, push the pistol forward.
4. Feel for Resistance: You will feel a small amount of initial resistance—this is completely normal. Keep pressing forward until the pistol fully seats and locks in.

Visual Learner? Watch the official step-by-step demonstration here: Proper MX1 & EVO Insertion Technique Video.

Quick Reference Fitment Guide

Watch these How To Videos for more information:

How to Extend the Barrel Shroud for the Glock 17/19 and the Canik.

How to Insert your firearm into the MCK EVO

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