i definitely understand you wanting a brake on a .300wby, I say it's worth a shot, as long as they warranty it. a barrel threading will usually run you about 120$ at a local smith, then you still gotta buy a brake. it's not a like a mosin nagant where you can go to amazon and find a threading set on the cheap either. the DEFCON 1 seems to look like an effective design to reduce recoil, but it's gonna be LOUD, the grizzly would probably be second best and less obtrusive. the added weight can help or hurt your accuracy, no way to tell up front, but you will probably be okay. good luck, let us know how you decide ad how it works. welcome to the forum.