Monday, February 10, 2014

How to remove and replace your Vz. 58's fire control group

This article was originally posted on another blog of mine in late 2010, but its content is more appropriate here, I think.

I'm going to deviate a little bit from the established nature of this blog, simply because I like to play Good Samaritan every so often and actually add useful content to the Internets.

You see, recently, I purchased a Vz. 58 steel trigger, to replace the plastic trigger my CZ-USA Vz. 58 came with. When I looked on the Internet for info on how to muck around inside the receiver, I found nothing, so I had to figure it out myself. Trying to remove the fire control group from this rifle without knowing how is really hard, and results in lots of unnecessary scrapes on your receiver, and a lot of fruitless banging and frustration. Removing the FCG after you know what to do, however, is really quite easy, if a bit tricky. I decided to write this to help people do it the easy way.

The parts can get a bit confusing. I use the same terminology Czechpoint does, and you can find a nearly complete parts list for the Vz. 58 at their website:
The title is not so much an accurate description of the content as it is all the search terms I used in trying to find info about how to perform surgery on my Vz.

Let's begin.

Firstly, and most importantly, you want to remove the magazine and clear the chamber.

Then, and this is why that last step was so important, you want to flick the safety off if it wasn't already, and pull the trigger.

If you followed step one, you should get a click. If you didn't, you should get temporary hearing loss and a hole in something.

Now, push out the receiver cover retaining pin. This pin likes to push out most of the way and leave about a fifth of itself still retaining the cover, so make sure it's all the way out. If you have difficulty removing the cover, this is almost certainly the problem.

Next, remove the receiver cover by pushing it forward from the rear, and lifting it up. It should come straight on out. Note the dual captive springs; it's important to line them up properly during reassembly.

Now, remove the bolt carrier assembly by retracting it all the way to the rear, and removing it from the top.

Finally, you can inspect the glory that is the Vz. 58 fire control group. When I first tried to remove the old trigger, I just banged on the trigger axis pin until I destroyed two pulled 7.62x54R bullets and gave up that approach. It turns out, the Czechs thought of their trigger axis and sear axis pins backing out and put in two little e-clips.

These e-clips hold the pins in despite the application of considerable hammering. These e-clips are simple to remove, but for God's sake do not lose them. Just take a screwdriver, or other fine implement, and flick them out. They come off readily.

Once both e-clips for the sear and trigger pins are off, tap the two pins out slightly from the left to the right. Tap the sear pin out first, then the trigger pin. Once they come out about a millimeter, there's enough space for you pull them out all the way with a screwdriver or your fingernails. They shouldn't fit tightly.

It'll take a little finagling, but it should be pretty easy to remove the sear.

Once you have, remove the trigger assembly. To do this, press the trigger up from the bottom, and compress the disconnector spring enough that the trigger and disconnector come free from the sear assembly.

Now you have the trigger assembly in your hands. To install your brand new trigger, simply tap out the disconnector pin holding the trigger and disconnector together, and remove the disconnector and disconnector spring.

Replace trigger, or work on the trigger, or make sweet love to it, or whatever you're going to do, and then prepare to go insane.

This next step is the only truly hard part in replacing the trigger on a Vz. 58. You must reassemble the trigger group, which means reinserting the disconnector spring, and then compressing the disconnector to just the right place that the holes line up, while holding the trigger assembly steady, and hammering the disconnector pin back into the assembly. You might be able to more easily do that with a pin vise, but I don't have one of those, so I enlisted my girlfriend to supply the requisite third hand, but found that the assembly is actually too small for three hands to fit on the blasted thing without me hammering our thumbs into pulp.

Instead, I found a pair of pliers, and that worked well enough. It's still a matter of trial and error, though, so be patient, and eventually the pin will work its way a little into the disconnector, and then it's just a simple task of tapping the little devil in gently.

Now that you have your trigger assembly back in one piece, you simply have to put it back in the way it came, and then pushing the pin back in. Do not put the e-clip back on the pin until you are 100% sure your trigger group works. I even went so far as to reassemble the entire rifle without the e-clips, just to make sure. Once the trigger is in there satisfactorily, start on the sear assembly.

It looks weird, but it's not difficult to do once you figure out what goes where. The sear assembly likes to come apart, especially that plastic thing, which I'm pretty sure is a replacement for an automatic mechanism, since it does basically nothing. Czechpoint doesn't sell this part, so if it breaks, you're SOL, I guess. Anyway, that do-nothing plastic thing fits with the large end toward the right, if your assembly came apart (mine did), and the sear fits with the long end basically sitting in the middle of the receiver, to hold the striker back before firing.

The sear group fits in so that the little tab jutting out from the bottom of the sear is pulled on by the disconnector. A little trial and error will make it fit properly. Interestingly, the sear and trigger pins are interchangeable, so don't worry that you got them mixed up.

Once your rifle's trigger works, simply slide the e-clips back onto the pins. This is actually easier than it sounds, if you use a screwdriver. They might not click, exactly, but if they look like they're on, they are.

Now you're ready to reassemble the rifle. Simply tilt the muzzle of the rifle downward, let the bolt flop forward in the carrier, and mate the carrier and receiver together at the cutouts in the rifle rails. Slide the bolt forward. Now if the sear engages the striker, that's a good sign. If it doesn't, you have more work to do. Remove the carrier and find out where you screwed up. If it holds the striker, pull the trigger, both to make sure the trigger group will release it properly and to prepare the partially assembled rifle to receive the cover.

Now take the bigger, top spring in the receiver cover, and align it with the topmost hole in the bolt carrier. slide it in, making sure the lower striker spring falls into place inside the striker (they call it a "linear hammer", since the actual firing pin is a separate part). Now slide the cover in most of the way.

Make sure the little tabs jutting down from the inside edge of the cover mate with the receiver, or it won't go on right. Once it's properly inserted, push in the retaining pin, and you're all set.

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