I would suggest you approach your uncle and offer to buy the rifle from him at a fair price that a stranger might offer him, not looking for any favors because he's your uncle. Or, offer to buy him a new rifle as a replacement that you might end up owning as well. And don't delay in doing it.

IMO, people make a huge mistake waiting for a relative to give them an old firearm. If the gun means that much to you, don't hesitate to buy it before someone else in the family takes a liking to it. If you pay a fair price, no one is in any position to cry foul.

As to speculation of what my intent was with the question, I was thinking of a NEW firearm that would start with me this year and have that as the beginning of the 'heirloom'. Something that was 'mine' and gets handed down to MY subsequent generations.

Simply a good quality shooter that looks nice and will stand the test of time for the coming decades and generations. Not talking calibers, just manufacturers and models; and probably something pretty mainstream.

What model and mfg. would you buy today and say, "I hope my grandson thinks of me when he takes this hunting."

^ This how I see it^. My commentary about a firearm that is an heirloom: it usually says something about the original owner, and that is the most treasured aspect of an heirloom. Now if it is a fine firearm all the better but that is not where the true value lies in the two that have been passed down to me.
I have an old colt single action army modified artillery model revolver that my sons great great grandfather carried as a member of the 1st volunteer Calvary (Rough Riders). My son is named after him and understands its significance. We occasionally shoot it. One day the pistol will be his to pass down to his son.
The second is an old double barrel Winchester model 21 that my grandpa bird hunted with. Papa used to get me after school and take me bird hunting 2-3 days a week. He taught me a lot about shooting and bird dogs. The walnut stock is pretty beat up from years of hard use and the blue is pretty worn. Every year atleast once, even though I can't hit for beans with it, I take the old side by side out. Just the dog and me and remember...
Both of those could be considered collectible but it's irrelevant....Neither will ever be sold. In that same vein, hopefully when I am gone, my son will find something special about one of my firearms....time will tell but ultimately that will be up to him.
If you want a nice gun, go get it and enjoy it. In the meantime, take full advantage of every opportunity to make memories with that six year old. It will be those memories that the heirloom he chooses, will link him to you, after your gone.

My heirlooms are a post 64 Winchester 94, grandpa bought it new for my dad when he was 16 (1976) and my dad gave it to me when I turned 16. I also have my dad's pistol that is the first gun I remember shooting when I was 5 or so, a colt trooper original (not mk2 or 3) 4inch in 22lr. Wouldn't trade either for the world. They will go to my son one day along with his single shot savage I bought him when he was 1. It's an old pull clock single shot. Not sure of year, pre dates serial numbers. Was the first gun I let him shoot, second was the trooper. Same day though.

As far as a modern heirloom rifle it looks like you have more than a huge pile of good suggestions. Good luck with your search.

I'm pondering the same thing currently. I think I'm going to go with something with a Mannlicher stock. So classy. Probably a Ruger K77RSI that Lipseys puts out in small batches. Or maybe a CZ.

I’ve never owned a CZ but have handled a few. They sure seem like good rifles for the money, presuming they shoot well. A lot of guys who hunt Africa like them (especially Europeans) so I’m betting they do.

I only have a CZ rimfire and scattergun, currently, and building up a little carbine on a 527 action. As you say, NP, good rifles for the money. Which I don't have an excess of.

I have great grandfathers 1903 colt hammerless pistol , 20 ga double barrel side by side ,
and all of my Dad's guns. Most special is Dad's Steven's crackshot model 26. He used this
rifle to feed his family during the depression. He carried it while running a trapline that
earned much needed $$$. Some nights he would earn as much as his Dad made working on
WPA programs. It is a true heirloom in my opinion.

good luck
MO

Apparently my grandfather left me all of his guns when he passed a few weeks ago. None are really worth anything monetarily to anyone else, especially with his love of engraving his name and DL# into them. Now they're really worthless on the market. But to me, I know when I receive them, I'm gonna cry like a little baby. He has a LLama that he hand carved his own wood grips for and an old Mauser that he built his own stock for as well. Granny's little .25. I didn't even know she carried. lol

It's the damndest thing though. I used to think I wanted them SO bad when I grew up and spent so much time with him. Talking about them. Him showing me all the little things he did to them. But now, they're just things to remember him by. I'd trade it all to have them both back.

Those are heirlooms to me

So... based on your clarification Andy, I'd spend some time wandering a few gun shows/shops and see what speaks to you off of the tables. And suggest you take your little man along as you explain to him the different types of firearms. A couple decades from now you'll be able to tell him the story of helping you pick out the gun that will eventually be his, and his kid's. Heirlooms are about good times and memories. And there are so many good makes/models/calibers these days, it's hard to go wrong anymore.

Agree with you on I would happly give those precious firearms up for another day with the previous owners of them.

Awesome suggestion...

HNF,
I am going back to my first suggestion, Montana Rifle Company. It is reincarnation of the pre-64 Model 70 but with improvements to safe gas handling and very good accuracy. It is ready to go out of the box with really good quality of construction. It has a quality that feels like it will last a lifetime and longer.

My choice was made for me when my Uncle brought home two Sako Pre-Garcia L61R Finnbear's from Germany in 1969. That is exactly what they are, heirloom rifles that have been passed from my Uncle and Father to both my boys and we hunt with them every year.

Earl