The .45 calibre is great for antelope and deer sized game.
A good place to start when developing a PRB load is around 45-50 grains of powder. From my experience the .45 is one of those calibers that works well for either fffg or ffg…though most of my shooting is done with fffg. Lots of people here will disagree on using ffg in a .45 calibre, to each his own.
PRB loads for hunting usually fall into the 55 grain to 70 grain range. My personal .45 calibre muzzleloaders fall into 55 to 60 grains for hunting loads. You'll not need to use big powder charges in the .45 calibre.
Conical bullets, maxi balls etc. usually shoot best with a twist rate of 48” or faster…though I've seen enough PRB barrels shoot conicals just fine, so hit or miss. Loads for conical are going to be in the 55 grain to 75 grain range. Most of my .45’s these days are PRB guns, though I still have one rifle that is just so accurate with conicals. It likes a load of 65 grains of fffg.
Regardless of your projectile type, you'll want a load that is accurate out to at least 100yrds, even if you limit your shooting to much closer shooting situations. I've taken maybe one deer at or maybe just beyond 100yrds, while the vast majority of my deer, taken with a muzzleloader, have been between 20yrds and 60yrds.
As a good published resource…Lyman had a Blackpowder loading book, that was fairly comprehensive. If you can find a copy of that publication, it would be to your benefit.
https://www.amazon.com/Powder-Handb...1&s=books&sprefix=Lyman,stripbooks,175&sr=1-2
or her!
