Well if you have a Mill & Lathe or a CNC machine you can make your own Muzzle Brake. If you noticed that there are about a thousand companies making Muzzle Brakes out there.
BUT which ones work as far as recoil reduction.
A lot of them are just a extension of a barrel, threaded, and holes drilled in it.
It all comes down to the PORTS and how they are made with the size, angle, how many, position of the Ports.
There are Manufactures that spend a lot of time/resources in development of a Brake. These Brakes are designed for the Caliber, FPS, Energy, Barrel. Not every Manufacture gets it right.
You would have to also look at "Manufacturing Firearm Parts".
For the most part having the equipment to make a Barrel Brake and then having the knowledge to do it right are two different things.
Also making for yourself or selling is a whole different thing.
If you copy another manufacture Brake there could be Patents. If you make a Brake and it malfunctions and there is an injury - well you could be in a big financial loss.
If you want a Barrel Brake that is good for recoil reduction I suggest that you do the research and purchase a Brake.
Just my opinion.