Had a 7 RUM sendero. Had Nate Dagily form Striaghtshotgunsmithing send me one of his V breaks and had it installed localy. Cost 150.00 total and it kicks less than my rem PSS 308. It simply amazing the amount of recoil reduction.
With that said I would not look past Shawn's break or the new Pain killer form Kirby Allen.
I have one of Shawn's on my 300RUM. It's the only gun I've ever put a brake on but I would compare the recoil to something less than .308. Surprisingly, it's no where near as loud as I had anticipated. I would recommend it though my experience is limited. I could shoot it all day if I could afford to.
The man himself installed it for me and the cost for brake and installation was $175 I think.
I had a Vais (spelling?) break installed on my .300 Winmag. Now, I wouldn't shoot the thing without it. It tames the recoil. It cost about $150 bucks to have installed by a gunsmith. It may cost more if they have to pull the barrell off the gun, but hopefully they can do it without such drastic measures.
I have a friend with and without the break on .300 RUMS. I wouldn't bother shooting the RUM without the break.
Terry in Glendale ARizona
I had a DE muzzle brake put on my 300 WM and to me and my buddy (who shoots a 243) has less recoil then his 243. I like it. Makes shooting the gun 10 times better, now that i don't have to worry about the recoil. This was my first muzzle brake ever.