Grandpa Mike, You asked a question I've been looking for, so I appreciated your question.
First post here, been waiting for e-mail confirmation, and decided to try and post anyway, to say thanks for the question!
I'm assuming pressure for book loads in .500 S&W is suitable for the .45. Just picked one up three weeks ago, and it sure opened my eyes. Ragged holes at 50 with the slow cowboy stuff. That is one fun rifle to mess with.
Can anyone point me to some data with the heavier loads that won't shake,rattle, and roll my little rifle loose.
Would appreciate it much. Guessing on my part, green on the Handi tuning and loading, though have messed with them quite a bit, but thinking mid 20,000 psi about right for what I've have found on sites here there and yonder.
You guys have a lot of good info here for the NEF's and H&R's, thanks a bunch!