I just "inherited" an AR-15 with an additional Colt 7.62 x 39 upper.

It belonged to my younger brother who just discovered that his new wife won't have a gun in the house, so he just gave it to me ( I also got grandpa's shotgun and his 10/22).

I'd be more concerned for him except that he doesn't seem to really care one way or the other.

The rifle and extra upper were gifts from our father six years ago and neither has been fired which shows just how much interest my brother has in guns.

My question is: What should I do with the 7.62 X 39 upper?

I have other rifles that shoot this round (AK & SKS's), and have maybe 2K rounds of ammo put up.

I already own one AR-15, but I've just never really considered an AR as a platform for the 7.62 X 39 cartridge.

Should I keep the upper for a rainy day, sell the upper to fund other projects, get another lower receiver for it, or just store it in the event of a future divorce or she gets a clue?

Just a couple other questions: Does this caliber require special mags or just a different follower? If I keep it and set it up as a complete rifle, what should I do to prevent caliber confusion?

In a related story, my father is on his way out here for a visit and is bringing their wedding presents, a Para Ordinance LDA for my brother and a Ruger .357 for the sister-in-law.

This could be a very good month.

I would just keep it,cost you nothing.

Quoted: I would just keep it,cost you nothing.

+1 never know when it might come in handy.

Keep it and shoot wolf out of it. Get another lower if you wish (it never hurts)

Your Sister in Law inherited your brothers balls and you get a rifle.

Seems like a fair trade.
I'd buy a new lower and have 2 rifles.

Then you can say that you scored 2 ar15s for less than 300 bucks.

Quoted: Your Sister in Law inherited your brothers balls and you get a rifle. Seems like a fair trade. I'd buy a new lower and have 2 rifles. Then you can say that you scored 2 ar15s for less than 300 bucks.

Yeah, I'd go that route too.

Quoted: Your Sister in Law inherited your brothers balls and you get a rifle. Seems like a fair trade. I'd buy a new lower and have 2 rifles. Then you can say that you scored 2 ar15s for less than 300 bucks.

Id say that is good advice.

Just a couple other questions: Does this caliber require special mags or just a different follower? If I keep it and set it up as a complete rifle, what should I do to prevent caliber confusion?

Yeah it requires a special magazine, and they are difficult to find.
The ones that work are hard to find, and are often called "frankenmags" for the way they look, sort of a cross between an AR and AK mag.
My advise since you already have several 7.62 X 39 platforms is to sell the upper and buy ammo with the proceeds.
But then again that's just my opinion.