Ok, So I have my AR (Colt SP1) and while speaking with someone from the forum it was suggested that I have a nice rifle & should keep it nice. No argument there... By keep it nice, it was inferred that I do not put a lot of rounds through it so it can really hold it's value. That makes sense. What doesn't make sense is having an AR that sits in my safe waiting for me to put it to use. As for home defense, it would not be my first option (unless the Zombies were crashing my driveway). I really enjoyed shooting my AR and would like to learn to master it. As a result, I have decided to buy/build an AR with a purpose. Perhaps several purposes...

I am not a hunter, (no particular reason why, just never learned), I am not a LEO nor am I one of those "the end is nigh, prepare for Armageddon" types, I just really like to shoot & want to do it well. I have a strange affliction that pulls me toward the 1911 & now my AR. I just enjoy the heck out of shooting them!

My point...

What are some uses for the AR that are functional?
Here is what I am thinking about...
I would like to get a rifle that has several hats.
An AR that I can use for practice & improvement of my skills.
An AR that I can learn to hunt with and have it as an effective rifle while hunting and an AR that I can shoot in competition (if I ever get so skilled).

Is it possible to make a rifle with these things in mind?
what is a 3 gun? Does that refer to this type of project?

Can you / should you have 1 receiver & 3 uppers?

Can you use 1 receiver & have a .308 upper & a 5.56/.223 upper?

These things are not cheap to shoot! It seems like a waste of time to learn to shoot a gun that you will not use and a waste of money to shoot a gun you cannot afford. Is it possible to build a gun that you can afford to plink and learn on & then swap the upper & go hunting & then swap again so you can compete? Or should I just get an oly and learn to shoot first? I don't want to go that route & I would like to keep my colt in good condition.
I guess my thinking is if you are going to do something, do it right the first time. I would rather have a beast of a gun that I can really use & then make nice when it counts instead of buying 3 rifles as I grow.
Any input, grounding or advice is much appreciated!
Thank you for reading this.