I agree with Lemoyne. Definitely research the concept of "point blank range" - it really makes sense and I just discovered it this year and felt like a real dumba$$ for not knowing it before now. Lets just say I had to learn it the hard way cause I didnt do my homework in time and missed the biggest buck of my life because I wasnt educated on ballistics of my 308 at long range. Still haunts me. Silver lining is I shot just under him, didnt clip a leg etc and caught him on a cam two days later. ANyway point is - do your homework and know your drops for all guns at the very longest distance you feel competent shooting. I just procrastinated and paid for it.
The BDC scopes are not dead on at each yardage by any stretch - Way to many variables. yes it will get you in the neighborhood but it is amazing how much a bullet can drop from 150 - 200 and especially from 200-250 (not that you want to be shooting a muzzleloader that far at first but also even for your regular rifles.)
I did not like the Nikon scope's circular reticles due to the circles. I prefer crosshairs. Nice this about Nikon is all the holdover points it will give you based on all the circles it has.
I, like you, will have maybe a max shot between 150-200yds. Which makes the Nikon BDC abit overkill. So here is what I got and I think you will like it as well - a Redfield 4-12 x 40 with accurange reticle (Leupold bought Redfield so its a quality scope at a fraction of the price). Back in the 70s and erly 80s Redfield was like "THE" scope in my parts of the woods then they were forgotten. The acurange reticle doesnt work for 50 cal but it provides a circle around the main crosshair that you can use as holdunder and holdover points and under the circle surrounding the main crosshair is a main second holdover point and then you can use the tip of the thick bottom duplex as another really long distance holdover point. You will have to do some testing to find out what these marks tr and anslate to your. For example if you zero in at 100 go to 150 with full power on scope and fire three shots at the target using your main crosshair. You will shoot low but raise the scope up to see if the group matches any of the holdover points on your scope. If not you will have an idea of where that point is for a future shot. Same at 200, etc. Some people and some BDC scopes are designed where you have to adjust power of your scope to coordinate with ceratin holdover points (when I am in the stand and a big one walks out - I dont want to have to sit there and adjust power on scope or try to recall which of the 6 or 7 holdover points to use. This is why the "point blank range" also simplifies things so much (especially is you are using a plain duplex scope).
By the way - I shoot a triumph Bone collector. I order a one piece medium extended mount for 1" tube direct from Talley and am really pleased with it. Word of advice - buy the tourque wrench (especially) and levels if you are doing it yourself.