I recently inherited a muzzle loader when my father passed. Thompson Center Arms Hawken. I understand the concept.... but how do I really learn where to get started so I can buy what I need, prep shots, amd SAFELY use this thing? I would love to shoot it and not just let it collect dust.

There are traditional muzzleloading forums,after that you just have to experiment. Make sure you really know how to clean one proper as well. Real black powder works the best in the older side locks. It may be a bit of an investment since you usually have to order it online but it’s worth it in my opinion. As far as safety make sure the ball is seated all the way down on top of the powder. I have that gun in .50 cal. Basic load would be 75 grains of black powder lightly lubed .015 patch over a .490 ball. I swab the barrel with a damp patch after every shot at the range just to keep it like shooting from a clean barrel. I can shoot multiples without cleaning if I want but if the ball starts to get harder to load you should swab, and maybe play with what your lubing the patch with, although spit works pretty dang good at the range. If you really take your time it should shoot as good as you can at 100 yards and in with open sights. If you decide you don’t like a patched ball you can buy conicals I know it’s a long post but your basically doing the same thing as a modern hand loader. I’m sure someone will come along and disagree with all this but whatever.

#1 is make damn sure that it’s not still loaded from last time it was used.

Here is an owners manual for your Hawkin if you don't have one:
https://www.tcarms.com/pdfs/uploads/manuals/Hawken_Manual.pdf

It should get you going in the right direction.

https://www.dixiegunworks.com

This is a very good place to get supplies and info. They are located in union city tn

One thing my old man always harped on me as a kid was to be really sure I had the ball seated all the way. He marked a line on the ramrod to be flush with the end of the barrel when fully seated. That also helped to make sure it wasn't double loaded per Wiley's comment. Have fun with it Thompson makes a great muzzleloader. I got a Thompson White Mountain Carbine when I was a kid and shot my first deer with it. It's about time to hand it down to my son.

Thank you so much! Time to start my homework!

And when you figure out how to cock that thing quietly and set the trigger, let me know.

Haha. I realized immediately that would be a problem.

I built a 50 cal hawken from a kit in the late 70s and have killed a few deer with it. I used to leave mine cocked without a cap when I was hunting and used these rubber caps to cover the nipple. Round balls never worked well for me, I shoot the buffalo bullets in mine. I think they are 550gr.

Take it apart and clean it. Make the hole is clear from primer to load.