All of my muzzle brakes are made using heat treated 416 stainless steel. This material runs between 28 and 32 Rc and is the same material used for most stainless steel barrels made today. All threads are single point cut in a CNC turning center or thread milled in a CNC mill to 2b specs. I will open brakes to any caliber the customer requests. There is no one size fits all here. I can also taper or turn a brake to a specified diameter and/or Cerakote for 12.50 per service.
As a general rule the larger diameter the more effective the brake is. So if you don't mind having the brake larger then the barrel and/or tapering it to your barrel rather than having it flush with the barrel, you'll have a more effective brake with a larger diameter. There is a noticeable difference between the Baby Beast and Lil Beast brakes on magnum calibers. That is why I usually recommend the larger of the 2. The port height is 30% taller on the Lil Beast and port height has a direct correlation to recoil reduction.
With my muzzle brakes, after about 45-50grs of powder you will reduce more recoil with a 4 port brake then a 3 port. This is powder charge weights not total capacity. This means short action non-magnum calibers like .243 win, 6.5 Creedmoor, and .308 are best for 3 ports. The transition from 4 to 5 ports is about 65-70grs. 4 ports tend to be all that is needed for the smaller magnums and most of the long action non-magnum cases. There is a benefit to a 5 port on cases about the size of a 300 win mag and up.