I have owned and sold 6 ARs over the years “All Colt” and never had issues with them with range use and just toying around. My observations are it is really a light rifle in construction and weight. Look at the bolt size as compared to an AK for example . Double the size of of everything and lets see what would happen ??
Just a thought
Why would you double everything?
Yea I’m not getting the purpose.
Do you mean increasing caliber?
You could look at a 308 model and those aren’t so light.
So… scale everything up by a factor of 2? You just invented Paul Bunyan’s rifle.
…REALLY!?!
What is trying to be acomplished with this? There are .308 ARs aplenty in the market. Is that what you are thinking? 
Were they not really Colts?
I’m not getting where your coming from. Care to explain and clarify why you think this is a good idea?