I think folks need to remember that simply saying "I'm a Hunter" is rather generic, especially in the black powder era. Consider today, you have two groups, sport hunters and professional hunters just in the English speaking world. Among the sport hunters you find black powder hunters, bow hunters, waterfowlers, bird hunters, dove hunters, big (African) game hunters, big (North American) game hunters, dangerous big game hunters, squirrel hunters, deer hunters, elk hunters, aligator hunters, fox hunters, moose hunters, boar hunters (with spear and with other means), some specialize, and some do all of the above.
Then when you talk about professional hunters, you find guides for most of the above, plus hunt masters for fox hunting, ghillies in Europe and perhaps on some large estates in America, not to mention the folks who are paid to thin out herds of deer in parks and other "no hunt" areas near where I live.
So I caution use of the very broad, generic term.
Now for the 18th century, you can easily find professional "meat hunters" who were specifically hired to supply a military garrison, a trading post, or a group embarked on a mission into the wilderness such as trapping or surveying or perhaps conducting settlers on a long overland journey. You will find "hide hunters" who are interested in harvesting hides for sale to folks who make it into leather. Some work for "companies", some work for themselves. Then there are "market hunters" who hunt for animals to supply a local market or markets. Compared to a "meat" hunter, the market hunter is more influenced by what the customers want..., and so might do more waterfowling or bird hunting than red meat or vice versa. Finally you have the subsistance hunter, who hunts for his own family's meat, and leather, and might from time to time sell off some surplus.
When you get to the 19th century, and Western forts, you may need to do some in depth reading. Did the fort have livestock? If it did then did they need a hunter to go shoot elk or bison? Did the officers hire a hunter anyway for although they had beef or pork, they wanted variety in their meat? Did the fort contract for a specific type of meat, so the hunter was hired to supply lots of bison which were salted and preserved in barrels for the winter? Was the fort a stopping point for travellers, and so there is a self-employed hunter that kills and salts animals and sells the meat to those passing through, while the garrison is fed "army beef"?
Finally, don't omit the possibility of the "hermit". Consider the character of "Bear Claw" Chris Lapp in the movie Jeremiah Johnson played by Will Geer. He tells Johnson (Robert Redford):
Bear Claw: l hunt griz.
Johnson: Griz?
Bear Claw: Grizzly bears, pilgrim. l collect the claws. l had one in that thicket back there, ready to shake hands until you came along!
Now true, this is a fictional character. I am also not suggesting that you don Geer's style of costuming as you said you'd wear cloth, but this character cannot be selling a large amount of claws. He's not suggesting there's a big market for grizzly claws. Bear Claw lives in the mountains because he chooses to do so. He is a hermit, a recluse. He lives mostly in solitude, but he has to get his powder and ball someplace, right? He also tells Johnson,
"You can cut wood and leave it up on the Judith[river]. Riverboat captains will leave you gold if you put out a pouch. Good thing to know, if times get hard." So Bear Claw does have contact with folks from "down below".
Johnson on the other hand is fur trapping, and the idea was to make some money doing so. So the point I am making is that you could very well have been employed at some other trade for years, attached to the army or the fort garrison, and when the contract ran out or you couldn't do that trade anymore, you didn't head back East, you stayed, and live near the fort, and so now you hunt, and sometimes sell some of what you have harvested for the odds and ends that you need. Like cloth, powder, shot, etc.
LD