First off, I’m not comfortable telling people what they should be spending their money on. I am comfortable talking about what I’ve experienced, and what I believe to be true.
.36 calibre & .40 calibre are wonderful for small game and generally fun to punch paper, stroll on woods walks and maintain your shooting skill. Of the two, my personal choice is the versatile .40 calibre. I say versatile, because I can not only shoot .390 or .395 RBs out of my gun, but I can use a heavy patching material and shoot .375 and .380 RBs, making the gun a nice accurate functional squirrel rifle. A day in the woods toting a .40 calibre, is a day to remember fondly. The .40 calibre is plenty of rifle to bring down deer sized game. My .40 calibre uses 40 grains of fffg, under a .390 patched RB, and is flat out to 125 yrds…that simply amazed me when I figured that out at the range. The gun is light and well balanced, not as light and balanced as a comparable .45 calibre, but so what…those little lead pills are fun to load, and easier to get into the bore than a .32 calibre.
After 40+ years of shooting mostly a .50 calibre rifle in one form or another, I’ve recently become enamored with the .45 calibre. The .45 calibre is just right where I needed it to be. 13/16ths barrel 42” long, will give you a gun that is light, with just a hint of heaviness at the front end. Make that barrel 36” in length and you will have one of the most carry-able, well balanced guns you can take into the field or to the range. I love big game hunting with a smokepole, and the .45 does it with less powder, and felt recoil. I can shoot this gun all day for less than what it takes to shoot a .50 calibre, and it shoots flatter than the .50 calibre or the big .54; were I going into the field on an antelope hunt, it would be a coin toss between my .45 or my .40 calibre rifles…probably the .45 though…
The .50 calibre has been my ”GOTO” calibre since my very first blackpowder rifle. The calibre is the legal minimum calibre for elk in any state. And it is very effective at harvesting big game. I cannot say anything bad about this diameter…it does as expected…I’ve killed many elk with a .50 calibre, I’ve killed more elk with a .50 calibre, than any other calibre. I’ve hit elk with a .50 calibre RB and I have found that shot placement and the bullets pathway through the body is critical. Shot placement is critical, but once accomplished, the animal is going down. My recommendation with the .50 calibre and elk; use a conical bullet of some type; things are just a lot easier that way. Though I have a personal fascination with the .45 calibre, the .50 calibre is way more efficient on big heavy bucks…hands down.
When I started hunting with a .54 calibre, everything changed. This is what happens when you throw elk on the platter of game animals, you’ll want to go .54 calibre. The .54 is just major awesome for elk. I could hit an elk sideways shoulder to shoulder, with a RB and crumple them in their tracks. With a .50 calibre RB, that’s a “No,No” shot, with the .54 calibre RB…it became my “GOTO“ shot, never failed me. That little bit of increased diameter, makes this calibre a hammer on any big game animal up through elk. Most of the time I recovered a flattened out projectile just under the skin on the far side from the entrance, though on antelope you’ll see some through & throughs. I cannot say enough about the .54 calibre and elk hunting. It is the most efficient calibre at converting grains of powder into velocity. My target loads in my .54 calibre rifles, start at 70 to 75 grains; hunting loads are between 95 grains and 105 grains (whatever is the most accurate)…so my .54 calibre guns are now brought out only when it’s time to verify performance at the range, followed by a trip into the woods to fill tags.