Rey, again I can just give you my opinion, take it for what it'w worth. In the 41 magnum I've used a 230 gr Keith bullet from a very old Saeco mold for about 45 years & have no idea how many deer I've taken with it but it would be dozens for sure. Also elk & 1 bear. The elk with the shoulder rig laying on it & me in the red shirt & you can see a piece of fat sticking out of the left hip. She was trotting up through the sagebrush & spotted my mule tied to a tree above me. When she stopped she was almost facing me but I could slip a 41 slug just behind the right front shoulder with my 8 3/8's Nickel S&W.
The bullet got one lung, the intestines hit a kidney & exited just in front of that left hip, she ran in a little circle for 5-6 seconds & piled up. It almost went through her length ways.
The cow elk that's laying in the snow was taken at 168 yds with an OM Ruger 45 & a 260 gr Keith & 23.5 grs of H110. My buddy "Duck" was shooting her with the range finder as I set up on my walking stick & got lucky with a double lung shot that threw blood in all directions, she was down & out in 20 yds.
Not sure I can tell you what a hard cast bullet is, not sure anyone has the same idea on hard cast. I make my bullets as soft as I can make them & still maintain accuracy. If accuracy starts to fall off & I don't think my load is fast enough then I make the bullet a bit harder. My #1 goal is accuracy & I always get exits.
My last cow elk was very big & was taken with a 250 gr LBT 41 magnum bullet at (I think) 74 yds. The bullet broke both front shoulders & exited, she never took a single step.
The 250 gr in a 41 is a heavy bullet in my opinion, a 280-300 gr bullet is a heavy bullet in a 44 magnum & a 275-325 gr bullet in the 45 Colt is a heavy weight, just my opinion.
I'm guessing you've taken a great deal of game with 45's & have a pretty good handle on what does & doesn't work as does several others here on the forum.
I do think you can "over bullet" any caliber & it's time to move up to something bigger, I'll say it one more time, just my opinion.

Dick