Then buy a centerfire rifle, and forget the flintlock! Really, you are asking to eat your cake, and keep it too. Flintlocks are short ranged firearms. They are designed to shoot RBs, not bullets, so you are restricted by the Ballistic's Coefficient to the range you can effective use a RB for hunting purposes. To get greater penetration, you have to increase the weight of the ball and ball diameter, but that slows the ball and causes a greater drop, or much greater recoil to get the same trajectory over a slightly longer range.
The most accurate long range FLINTLOCK I have shot, or seen shot is one in .40 caliber, and we hit a bang plate hung at 135 yards on a calm day with it. The powder charge was 60 grains of FFFg Goex, with the 90 grain .390 PRB.It seems to shoot " Dead on. " In actuality, the gun had been zeroed for 50 yards, so that the ball was still on the way UP at that distance, and arced higher to reach the 135 yard mark and hit the target within a couple of inches of the aiming point. The ball has a very low B/C, and is running out of gas. I don't know anyone who would recommend the .40 cal. PRB for hunting deer beyond 50 yards, and most would prefer it to be used at half that distance, taking head and neck shots.
The .45 shoots a 127 grains ball fairly well at distance, but after 100 yards, the trajectory drops off rather quickly.
The .50 shoots a 180 grain ball fairly well, too, and obviously carries more energy for penetration because of the added weight. But past 100 yards, it also begins to drop.
I do have a friend who killed a deer at a measured 175 yards with his .62 caliber flintlock, but he built that gun, and knows it in and out, and is one fine shot. Even he admitted he was guessing on the amount of hold-over ( the back of the deer) when he made that shot, as he does not practice taking shots at that distance. The .62 shoots a 325 grain ball, and, while it has the energy to kill game at long ranges, it is also dropping like a brick beyond 80-100 yards, depending on the load. Ball, or bullet, placement is everything with these guns.
Oh, some of these new shooters put scopes on these guns, in hopes of stretching the range, and not ever having to learn how to shoot open sights, or even peep sights. You may be able to see the target at longer distances more clearly, but you still have to figure out how much to hold over the deer to put the ball on target. Frankly, a Flintlock with a scope on it looks pretty silly, to me, but then, I am an old traditional flintlock shooter. To me, that scope would be like putting a jet engine in a Model T Ford.
I make allowances for shooters with vision restrictions who still want to hunt, and make good shots on the game they stalk, but these experienced hunters are not looking for 150 yard Plus shots. They are still stalking to within 50 yards to take a shot.
Short range shooting is what flintlocks are all about. They require a bit more knowledge to shoot accurate, and that adds a handicap to the hunter, that increases his satisfaction when he take game with his rifle.
Do not feel badly about yourself if you are not ready to be that kind of hunter. It often takes years of experience before hunters decide to set aside their repeaters, then go from a single shot cartridge rifle, with scope, to open sights, then to MLers, and finally to flintlocks. We probably draw more flintlock shooters from the ranks of Traditional Bow Hunters, than we do from modern cartridge shooters.
Best wishes.