Welcome Rover! There's a thread in the FAQs and Help sticky on that topic, I've used both, a 16oz MRR is more effective than half again more weight used in the same rifle with the same loads IMO, and the dead weight is not as carry friendly as the MRR.
You can get a 16oz C&H MRR for $35 from MPC if you're interested, but as Bob said, not necessary at that load level unless maybe you have a bad shoulder, that's pretty mild recoil, Remington factory 405gr loads clock well over 1400fps and they're a pussycat to shoot. I've shot 525gr cast bullets at over 1700fps in my 45-120 BC with a lead filled pipe that weights over 1½lbs in the stock at first, then the MRR, the MRR does a better job at reducing felt recoil, all else being equal.
Tim
