Disassembly and Reassembly of the CZ70 Semi-Automatic Pistol

The post-World War II Czech Army considered the CZ38 pistol to be minimally short of a total failure. This was primarily due to the pistol’s 9mm Short chambering, the large size, and the stiff action. So after the war, they insisted on and eventually adopted a design inspired by the Walther PP that incorporated a few mechanical improvements. This pistol, known as the CZ1950, was chambered for the 7.65mm cartridge, which we know as the .32 ACP on this side of the pond.

Like the CZ38 before it, the military eventually decided the Model 1950 didn’t measure up to military standards for reliability. Thereafter, the Model 1950 was limited to use by the Czech police, with a smattering finding their way into civilian hands. Reliability problems continued to plague the CZ1950. Changes were made to eliminate them in the late 60s, and the troubled Model 1950 became the CZ70, also chambered for the 7.65mm cartridge.

When that pistol’s production ended in 1983, it was replaced by what is considered to be "the best of the Czechs," the CZ75 (see American Gunsmith, January and February 03). Thousands of CZ70s (also known as the Model 1970) have been imported to the U. S., so it’s not unlikely one could show up at your place for service at any time. Here’s what you do when that happens. Field Stripping After donning your protective eyewear, drop out the mag, check the chamber, and depress the takedown latch (#35).

It’s on the right side of the main frame above the trigger guard. Get a firm hold on the slide. The recoil spring (#10) is a strong one. Pull the slide all the way to the rear, lift its back end, and control the spring pressure working against you as you remove the slide to the front. At one time, CZ70 grip panels (24 and 27) were held to the frame by a sturdy metal clip. The model shown here has a single grip screw (#15). Back it completely out and remove the grips.

Slip the recoil spring off the barrel (#43) and you’re done. Detailed Disassembly Invert the slide. Near its rear, between the finger grooves, you’ll see the firingpin lock (#9). Press it down with a small tool, hold it down, and bump the rear of the slide against your bench. The firing pin (#7) may or may not come out. If not, secure the inverted slide between padded vise jaws and depress the lock again. As you hold it down this time, use a small-diameter drift to push the firing pin out the rear.

Now carefully ease off the pressure on the lock. If you move too quickly, the lock spring (#8) which also serves

as the firing-pin spring, will exit your work area. The pistol has a loaded-chamber indicator (#3) that sticks out noticeably from the left side of the slide when around is present in the breech. This occurs because the indicator is in contact with the extractor (#6), which pivots on the extractor pin (#2) when its hook end rides over a case rim. Conversely, when no cartridge is present, the extractor spring (#5) feels no pressure and therefore doesn’t act to move the indicator outward.

Now drift the extractor pin downward until the entire assembly—extractor, spring, and indicator—can be taken from the slide. Nothing’s stopping you from taking a look inside the firing-pin tunnel right now to find out why the firing pin failed to drop out as it should Before further disassembly, the hammer should be thumbed to its full forward position. have a few minutes ago. Chances are it’s crud of one form or another. Clear it out and clean up the pin, and then we’ll move on to the main frame.

Move the CZ’s safety to its "off" position (with the red dot showing). Pull the trigger and thumb the hammer forward. Invert the frame with the empty mag well upward and secure it in your bench vise. Things will be easier from here on if your vise can be unlocked, rotated, and relocked. Here, the arrow indicates the well-seated spring retainer. Just visible under it is the additional spring that prevents the magazine from rattling within the grip frame.

D The spring retainer (#26) is positioned in a slot milled into the grip frame. Grab onto the retainer with needle-nose locking pliers and pull it free. Having a little trouble? Drift the stubborn thing out as you would a too-tight dovetail sight base. (Note: You may be handed a CZ70 with a spring under the retainer. Its job would be to provide tension against the magazine and prevent it from rattling around.

When you remove the retainer, that extra spring can be gently pried from the grip frame.) Now pick the mainspring (#25) from the hammer strut (#24). The hammer bolt (#19) has a nut (#40) holding it in place. A wrench from an automotive ignition kit will fit that nut perfectly. So will a set of smooth-jaw parallel pliers. In either case, once the nut has been taken off, the hammer bolt can be drifted to the left side of the frame, releasing the hammer, which is lifted away with the strut attached.

If you need to replace either the hammer or strut, the two can be separated by drifting out the strut pin (#22). It will be necessary to reposition the frame in your vise to access the sideplate (#39). It’s secured in

place by the trigger pin (#31), sear pin (#38), and a sharp, flanged front end that interfaces with a matching cut in the frame. Don’t drift the trigger and sear pins clear through at this time; there are too many springs and other parts that would be freed up before the sideplate can be taken off. Instead, move the trigger and sear pins inward a maximum of 1/4 inch, then treat the plate as you would the same component on an S&W revolver.

To be precise, use a wooden dowel, the handle of a screwdriver, or the handle of a hammer to partially dislodge the plate by striking the grip frame opposite the plate before withdrawing it from its flanged frame engagement. As careful as you may be in the step above, the trigger bar (#28) and trigger spring (#29) could tumble out when the sideplate is reof avoiding this is to relocate the entire frame to your bench top (plate side up) and applying the dowel or tool handle to the plate side of the grip frame.

So positioned, you may be able to start it off without disturbing what lies beneath. There’s an additional advantage to this approach.

When the plate is off, you can take a really good look at the inner assemblies and either remember CZ70 .32 ACP Semi-Automatic Pistol 1 Slide 2 Extractor Pin 3 Cartridge Indicator 4 Rear Sight 5 Extractor Spring 6 Extractor 7 Firing Pin 8 Firing Pin Lock Spring 9 Firing Pin Lock 10 Recoil Spring 11 Hold Open Latch Spring 12 Hold Open Latch & Ejector 13 Hold Open Hinge Pin 14 Grip them or make a sketch of their relationships.

Once you’re comfortable with your newly gained knowledge, drift the trigger pin through and remove the parts it held together, either 28 Trigger Bar 29 Trigger Spring 30 Trigger 31 Trigger Pin 15 Grip Screw 16 Safety 17 Safety Plunger 18 Safety Spring 19 Hammer Bolt 20 Sear Spring 21 Sear 22 Hammer Strut Pin 23 Hammer 24 Hammer Strut 25 Hammer Spring 26 Spring Retainer 27 Grip 35 Takedown Catch 36 Magazine Catch 37 Magazine Catch Spring 38 Sear Pin 39 Sideplate 40 Hammer Bolt Nut 42 Magazine 43 Barrel as a unit or separately.

Your next target will be the sear assembly (#20 and 21). Drift the sear pin through, but leave your drift in the hole. Slowly pull out the drift