stock for ar15

When I assembled my AR, it all went smoothly, until I noticed that my stock was visibly canted towards the left. At first I didn't think much of it, then I got to thinking about it. I tore it down, and found that when I tightened castlenut, I torqued the nut so hard that I made the endplate...

Just got a magpul compact buttstock. I am putting this on a Colt with a 20 inch barrel do I need to change the buffer tube or use the one that came in my rifle Question #2 What is the name of the part that goes between the buffer tube nut and the lower? It holds the spring and retainer pin for...