I use to work for KDF. I have installed and shot a bunch of muzzle breaks.

They serve several purposes. First they do reduce recoil. All the ones we tested and we tested everybody's, worked and worked well. Second they allowed you to keep your sights/scope on target. Third, they dissapated sound and made it difficult to determine from down range where the shot came from.

There are a couple of negatives. Sound they did not increase sound, they redirected sound. Instead of sending sound down range they sent sound sidways. Kind of like when someone faces you and talks to you and turns around with their back to you and talks to you. Same sound different direction. Muzzle blast. Again instead of being blasted down range it is going out sideways. You must be sure there are no objects to the side of the muzzle when you shoot. Those high speed expanding gases diverted by a tree trunk or boulder can sting worse than a mad blondes slap!

VIAS brake claims are good marketing, nothing is changed any more than the other brakes. All brakes effectiveness was based on perception. In the VIAS Sound and blast is directed at a slight angle forward. The perception is that it is quieter. Well from the shooters stand point it is indeed. But noise is not reduced. It's just going a different direction. I can tell you that from the shooting stand point I came away with the perception that the VIAS didn't reduce recoil as much as the others. But we were never able to measure that. And, I was shooting a lot of rounds through the KDF brake. I could feel a bad round. None the less the recoil was reduced.

Places for muzzle brakes. Heavy recoiling target or varmint hunting rifles. We made a 4 inch long KDF style brake and put it on a big 50 cal BMG long range target rifle. It worked better that ony of those tank gun brakes. You didn't want to stand to either side of it when it fired, even with ear muffs on.

We had a .22-250 with a brake on it and there wasn't a better gun for long range prairie dog shooting. It was vary easy to pick up the misses at long rang in the scope. Recoil didn't pull the scope off target. In the same light with virtually no recoil it was much easier to see the red mist effect and verify your hits. Of course the other thing that makes the muzzle brake work so good in these venues is they are normally shot while wearing hearing protection.

I have one rifle with a Muzzle brake, it is a K-15 in 308 Norma Mag that was given me when i left the company. It came with the brake.