I have a Kimber 300 WSM and I feed it 180gr Barnes TTSX. It is even lighter than yours I don't use the muzzle break at all. The kick is not bad. I call it the Tasmanian Devil kick blahhhh and it is over. Not hard just a quick jolt. I have other 30 cal rifles that aren't magnum so I wanted to use 180gr to get more ummff on large game. Lighter game I use the 06 or .308.