I have a ported Marlin .450 and unless you really need the brake I wouldn't put it on there. Though they do help reduce recoil. We have a 7MM mag that someone gave us that has a muzzlebrake and my buddies 11 year old son shoots it with no problem. Though like it has been pointed out they are very loud and at a range make sure you shoot down on one end and not underneath a cover. If I shoot mine I tell them to stick me at the far end and when I show them what I'm shooting they agree. If you get one and the recoil is too much you can put a different recoil pad on there and not make it so loud.