Anyone have any experience with these brakes?
Yes, I just recently put a brake on my 300 WM. It was so effective I decided to put one on my 375 H&H.
THEY WORK. They do reduce recoil dramatically. My 300 WM has a heavier brake and its not much worse then my 257 Roberts in the recoil department.
I put a smaller brake (not so heavy duty) on my 375 because I didn't want to add a lot of weight since its a hunting rifle. It now recoils about like a 30-06.
Even on lighter rifles like 22s, 223s, etc they work, they eliminate a lot of muzzle jump.
You will need to make sure you wear ear protection, which would be stupid if you don't use them with or without brakes.
The brake is going to come with a small hole which should be enlarged for your caliber when its installed. That makes sure its lined up with the bore.
Make sure you tell your gunsmith to bore it .20 over size. Meaning if you are putting the brake on a 308 it needs to be bored .0328. Larger is OK, but never smaller. Screws up your accuracy when the bullet bounces off the side of the brake.
Some smiths will try to bore the brake smaller, DON'T LET THEM, go with the Brake Manufacture recommendations.
Like I said, they work, now I'm lining up more of my rifles for brake instillation.