Not to cause a riot, but I wonder about your 250 - 300 yard "good possibility" statement.
I am sure there will be a few who claim to have killed many, many an animal with a muzzleloader at 400 yards.
Back when I first got into muzzleloading, I wondered how far was too far.
I did a little numbers crunching, and I figured that with my muzzle velocity being 2200 FPS, and a ballistic coefficient of .210, my DOWN RANGE velocity was not high enough to expand a bullet at 300 yds.
Not even close.
Talking to Barnes bullets, who makes the muzzleloader bullet I use, the velocity required to expand their bullet, reaches its MINIMUM FPS at 150 yds out of my gun.
Sure, that muzzleloader will chuck a bullet 300 yards. But the foot pounds of energy at that range, and the velocity that it has are not enough to make the bullet work properly.
I regularly practice on paper at 200 yards.
Not because I will ever take that shot, but because I figure that if I can make a 200 yard shot consistently, I will always be able to make a 100 yard shot.
But for me, I wont take a shot at an animal knowing that my bullet wont perform properly, not even if I figure I can hit it.
Thats a personal choice.
The change is scope regulations didn't alter the effective range of my bullet.
It made hitting paper easier at long ranges.
I would look into your set up before taking a 300 yard shot at a living thing, with a muzzleloader.
Look at your bullet. How much speed it needs to expand.
Look at your muzzle velocity.
Figure out what the effective range of your set up is before you go out and buy a scope thinking you can now shoot 300 yards.
Just my opinion.
Is it worth it?
Obviously this will start an argument.