Hello everyone, hope all is well

I was hoping to get some advice here as I am sure I'm not the only one to go through this.

My father is getting older and he wants to keep our family firearms including pistols protected by passing them down to me but he is unsure of the laws and wants to be covered on all ends.

What is the best recommendation on how to go about transferring all of his firearms over time into my name? I have my firearms purchaser ID card.

Go to a FFL with any firearm we believe was purchased "on record" and have them transferred into my name?
Leave them in his will to me and I will inherit them? Do not want to have to pay tax on them if that could come up if we go this route?
Do pistols complicate things?

Basically what can bite us here, want to do the right thing. Would be heartbroken if we had any unwanted consequences with this.

Thank you kindly!