I have a 12" SSK Mag-Na-Ported barrel. Very pleasant with full power 300 gr. Hornady HPs, upper edge of pleasant with 350 gr. Hornady SPs, attention getting with 400 gr. Speer FPs, Beyond comfort with 500 gr. Hornady SPs, most brutal gun I ever fired with 600 gr. leads.
A break would make it more comfortable.