CZ Kadet 20 round magazine

CZ Kadet 20 round magazine

The magazines for the CZ Kadet .22 caliber pistol hold a maximum of 10 rounds. The only way to obtain higher capacity mags is to make them yourself. The following pictures and descriptions show how I did this. It was a fun and challenging project.

***WARNING*** I highly recommend that you experiment with JB Weld prior to making the 20 round magazine. A mistake in application could result in two ruined magazines. For a person who likes to "tinker," it's a fun project. If you don't like to "tinker," don't try this.

To make a 20 round magazine, you need one Kadet .22 caliber magazine and one 9mm ten round magazine. A welder is not used at all during the conversion as it is held together with JB Weld.

Here's how the modification was performed: take one Kadet magazine and one 9mm magazine and draw lines around the mag bodies. A Dremel tool cutting wheel was used to make the cuts. A table grinder and file were used to perform the finishing touches.

Cut-to-shape a piece of cardboard and push it through the bottom of the Kadet magazine until it reaches the top. It must be a snug fit as this will prevent the hot candle wax from running through the magazine.

Now turn the Kadet magazine upside down and place into a table vice. Take a small candle (the type found in aluminum tins) and heat the wax with a propane torch until it is liquid. Then pour the hot candle wax into the magazine. This is a multi step process as you'll need the wax to cool inside the mag before adding more hot wax. Once the wax has been fully added, you'll need to clean it up. Be prepared as you'll get wax everywhere and it will be a mess. But, it cleans up easily.

After removing the excess wax, take a cotton Q-tip soaked in alcohol and clean all metal surfaces in the mag body thoroughly. This has to be clean for the JB Weld to "stick." Place pieces of paper towel all around the .22 caliber insert to make a sealed fit. The paper towel prevents the JB Weld from dripping through the entire mag.

Push the wax, with a cleaning rod, so it extends through the bottom. Look at the wax to ensure it is a good mold. It doesn't have to be perfect, but there shouldn't be any major flaws.

Now place the 9mm mag body on the Kadet mag body and secure with masking tape. Ensure the tape pulls the two mag bodies together for a tight fit. JB Weld will leak through the seam, so you'll want to cover this area. Obviously, the holes in the 9mm mag need tape too.

Now cover the entire magazine with paper or masking tape. You do not want the JB Weld sticking to any exposed metal. Mix the JB Weld, per the instructions on the container, in a soda can cut in half. Then heat the soda can in a pot of hot water to make it more liquid. Do not get it too hot or there is a chance of melting the wax mold. Candle wax found in a tin has a melting point of about 110 degrees. JB Weld cools fairly fast and a hair dryer helps to make it more liquid. The hair dryer is pointed at the mag body to help warm it up too. You WILL make an absolute mess, so be prepared.

Once it was dry, a dremel tool was used to remove the excess JB Weld at the bottom of the mag. Then the wax was chipped away and the remaining amount was pushed out using a cleaning road. There were no exposed pockets of air inside the JB Weld cavity, but this cavity needed to be filed and sanded to allow the follower to slide easily. A file and dremel tool was used to flatten the JB Weld to attach the floorplate.

The inside of the plastic floorplate was "gutted out"with a dremel tool and filled with JB Weld. A thin piece of metal (encased in JB Weld) was used to reinforce the bottom of the mag where the spring pushes against. A rolled up piece of paper (with tape enclosing the bottom) was used to displace the JB Weld for the compression spring. A hole was drilled through the bottom of the floorplate to enable a "punch" tool to compress the the spring. Obviously, the spring must be compressed to remove the floorplate. The floorplate is held onto the magazine body by friction fit.

Afterwards, I noticed that the removal of JB Weld from behind the spring hole was not necessary. The length of the compressed spring does not allow the rear of the follower to touch the plastic floorplate.

The metal end cap (lack of better words) for the bottom of the spring was taken from a Ciener M16/22 magazine. I cut it down in length, but the diameter was perfect. The follower was modified adding a piece of round plastic to use as a spring guide. The black plastic was cut from a Papermate writing pen and works great. Make sure it is glued on straight as it's impossible to remove later. The compression spring was purchased from Tennessee Coil Spring, Inc in Kingston, TN. This was a special order spring that was made for me while I waited at their facility.

***Special Note*** You'll want to cut the 22 mag and the 9mm mag bodies in such a way that the magazine curves just a very little. The curve or angle is so slight that it's difficult to see. You have to lay it on a table to notice it. You want to do this to allow the cavity for the follower to be somewhat centered (front to back). The idea is to have adequate thickness of JB Weld all around the cavity. Refer to the pic with the two white lines. You'll see how the mag curves/angles ever so slightly. This slight angle does not affect function or fit in the pistol in any way.

I have about 500 rounds through this 20 round magazine and reliability is 100% as long as I use standard velocity ammunition. Not all subsonic 22s cycle reliably, but this is not due to the magazine.

Loading 20 rounds is not easy on the thumb, so a 9mm mag loader was modified for 22s. Plastic was removed from the "arm" that pushes down on the cartridge so as to fit between the feed lips. In addition, a hole was drilled and steel pin epoxied in place to hold the magazine by the mag catch hole (see pic). It works perfectly.

Click on the link below to see a video:

CZ Kadet with 20 round magazine: