Rich, I was using 300 grain Sierra SPBT's in my H&H in the late 80's….purchased in the early '80's.
They were terrible bullets, came "completely from untogether" when contacting an animal…..wouldn't even exit a deer or an average Black Bear with a broadside hit on both. The bullets just disintegrated…..only found small pieces of jacket!
I heard that apparently, those produced at a later date than those I had bought were much better bullets. Though, I'll never know. I have never nor will ever, buy another Sierra bullet!
I contacted Sierra about my findings. Their excuses/reasons for my bullet failures were absolute BS…..I was pushing them too fast,I was using the wrong powder, the rifling was too sharp!
Hence the reason for my attitude toward Sierra!
I apologize for the "derail", 35+ years later….I'm still PO'd! memtb
There is a means to figure that out on a web site that I use. I can't guarantee it's accuracy…..I guess that I believe it in "blind faith"! memtb
Here's a link:
https://shooterscalculator.com/