Quoted:
I am looking at buying an upper and lower instead of a complete rifle.  they will both by BCM.  My question is for the BCM lower is the stock adjustable or do you have to get the intermediate buffer system.  If the stock is adjustable already what does having the intermediate buffer system get you?
Also,  If i get an upper of the website with a BCG and charging handle is that all I will need?  beside iron sights and mag?