If you purchased the full magwell kit, installation is quite straight forwards as it is a simple parts swap for the original magwell assembly. Nevertheless, if you don’t feel comfortable doing this yourself, any gunsmith will be able to this in a couple minutes.
Step 0:
Inspect your magwell kit and check for proper function. Slide in your magazine/magazines and check that they all fit, click in properly and slide out under their own weight when the release lever is depressed. The Magwell is manufactured to very tight tolerances to minimise any play when the magazine is attached. All assemble magwell kit are quality controlled and calibrated from us, but, if your magazine is slightly out of spec and doesn’t click in properly, there are several things you can do to fix it.
Step 1:
Remove the magazine from your rifle and check that the chamber is empty and rifle is safe to work on. Remove your bolt and set it aside.
Step 2:
Unscrew the two action screws holding your barreled action in your chassis or stock and remove the barreled action. If you have an enclosed fore-end, then dont forget to remove to cover. Clamp the barreled action in a soft jaw vise, upside down (magwell facing up) for easier manipulation or place on shooting bag. Be careful not to loose your action screws and recoil lug, as sometimes it like to stick to the action and fall off at the worst time.
warning: use metric bits as all CZ 457 used metric hardware
Step 3:
Remove/completely loosen the two screws holding on the original magwell. Remove the old magwell assembly. Just for fun, inspect it thoroughly, there is a significant chance it is cracked somewhere and you didn’t even know about it. Don’t loose the screws, you will need them in the next step.
Note: If you purchased just the magwell and ejector insert, jump the step 3.1 lower down on this page.
warning: use metric bits as all CZ 457 used metric hardware (3mm hex for magwell screws)
Step 4:
With the old magwell off, use the opportunity to clean your action. 🙂 Then, position the new magwell in where the old magwell was and loosely thread on the screws you took off your old magwell. The front one is a bit tricky, as it is directly under the mag release lever. You can depress the mag release lever to give you better access. The long screw goes in the back and the short screw goes in the front. Make sure that the mag release lever is on the side of the barrel.
Once Installed, check for function by inserting and releasing the magazine (with no ammunition!).
Step 5:
Gently tighten the screws. The threads on the action are not too long so do not exceed 2NM of torque.
Step 6:
Reinstall your barreled action in your chassis or stock. Make sure it se seated well and reinsert the action screws. Gently tighten them. Then stand the rifle system up on its buttstock and give it a few light taps against the table/workbench, to ensure it is seated correctly in the back of the chassis and against the recoil lug. Torque specifications vary, but for an aluminium chassis, do not exceed 5NM. For wooded stocks, this will be less. Please consult the manufacturer for exact values.
Step 7:
Check for correct function. Make sure your rifle is clear and safe and reinsert the bolt. Cycle the bolt (with no ammunition!) and make sure it cycles smoothly. If the bolt gets stuck before you are able to close the bolt, check your work again.
Troubleshooting (no pun intended):
1) You may have installed the magwell backwards. Make sure that the mag release lever is curved towards the barrel.
2) You bought the incorrect ejector insert. If you have a left handed rifle, you have to purchase a left handed ejector and vice versa. A right handed ejector block will not work in a left handed rifle.
3) Something is loose or misaligned. Check your work and make sure there is no play in the ejector block. If there is, remove the barreled action again and tighten the 4 Torx screws that hold the ejector block in the magwell. They are threaded into aluminium, so don’t apply too much torque (max 1NM). Use blue Loctite to secure them. Also, make sure the screws attaching the magwell are tight. If not, retighten them.
Magazine does not click in:
Please be very careful and take very small steps when making permanent adjustments. If you are not comfortable doing this yourself, please seek a gunsmith to do this for you. Once changes are made, you void your warranty.
1) Adjust the ejector insert
There are a few tenths of adjustment available in the ejector insert. To adjust, loosen the 4 torx screws that hold it in the magwell. Insert your magazine. If it clicks into place, perfect. Keep pressing the magazine into the magwell (up and to the back against the ejector) and tighten the ejector insert screws in this position. Test for function again. If everything works, continue with the magwell installation.
2) File down the catch ledge on your magazine
Especially original CZ plastic magazine may be slightly out of spec, or slightly deformed after prolonged use. When the magazine is inserted hundreds of times, it can force some plastic down and extend the catch lip of the magazine. Take a small file and clean up (file down the catch lip). Make very small adjustments, usually a tenth of a mm will do the trick. Do this, if the issue is only with one or two of your magazines and the rest work fine. If it’s the same issue for all magazines, go to option 3.
3) File down the top surface of the magazine release lever
If option 1 and 2 did not work and it’s happening with all your magazine, you may want to slightly file down the top surface of the mag release lever. This is quite difficult to do correctly as the surface is very small. Please take your time. First measure the overall length of the mag release from the top surface to the bottom, to get a reference dimension. Place the mag release paddle in a soft jaw vice. Get a small fine diamond file and then gently file the top surface of the mag release lever while maintaining the correct angle. You can also do the reverse by holding the mag release lever in your hand and grinding it on a flat surface, but we found this to be even more difficult to get right. Make very small adjustments, usually a tenth of a mm (0.1mm) will do the trick. File, measure, test, repeat until it works. This will effectively lower the threshold for the magazine to click in should therefore fix the issue.
Magwell and ejector ONLY installation
Step 3.1
As you have purchased just the magwell and ejector insert, you will need to install a magazine release lever yourself. You can use the original plastic mag lever from your old magwell or any other compatible lever you might have.
If you are using the original CZ mag release, you will need to remove it from the old magwell. Hold on to the lever and use a small punch to drive out the pivot pin. Be Careful as it is spring loaded. Remove the lever, spring and pin and install on your new magwell.
The process is slightly fiddly, and the spring likes to fall out during installation. Use a bit of grease or similar thick lubricant to keep it in place during installation.
Insert the pin from the bottom of the magwell, so that it does not protrude inside. Insert the mag release lever and position it so that you can sell the pin lever hole and magwell hole aligned. Then press the pin through from the bottom. If more force is required, you may need to press the pin against the table, while maintaining alignment.
After you have successfully installed your mag release lever, check for correct function by inserting an empty magazine and releasing it with the lever.
After correct function is verified, continue with step 4.
Happy shooting!