There are aluminium Picatinny rails and steel Picatinny rails for CZ 457 rifle. (Also sometimes reffered as scope bases.)
Picatinny rails made of aluminium usually have larger tolerances, and as a result they fit always fine and slide easily on (find such here from Toni or here original from CZ).
With the steel Picatinny rails [such as this one from JKN] some CZ 457 rifles run into a slight issue - the tolerances can be too tight, and if the dovetail on the CZ 457 receiver is just a little larger, it may be very difficult to slide the Picatinny rail on CZ 457, or it may be not possible it all.
It happens only in small number of cases, but it can happen. Therefore we put together the guide on how to fit such Picatinny rail. The good news is: it is easy to do, and you do not need any special tools for it.
What will you need for fitting
- 280-grit sandpaper, or finer
- flat surface
How to proceed
- Put the sandpaper on flat surface, ideally metal.
- Sand the base of the Picatinny rail using even longitudinal strokes along the sandpaper. Be sure to sand the whole bottom surface evenly.
- After slight sanding, attempt to slide the Picatinny rail on your CZ 457 again. If necessary, sand it down slightly more.
Once you can slide the rail fully in, you are good. Now you only have to screw the screws in. Which torque? The steel Picatinny rails require 2-2.5 Nm torque (aluminium require 1 Nm torque).
