Chris,

Nice note and glad you are getting good success with 4198 in your NfB loads. That powder has been my "go to" powder for years, probably based upon early articles by Ross Seyfried.

I like your comment: "In the case of NfB loads, I know some of those views differ. Please continue to disagree; that's how we get better."

BTW: My loads in my 500s have used both 340 gr cast bullets and 450 cast bullets.

My 500Ex Trolley weighs 9.5# and my 577/500 Mag Allport is slightly heavier