Best parts to build an AR15?
 

First question. I am getting that building an AR15 is like a set of legos. So do all the parts fit? Like if I buy an upper from one place and a lower from another will they fit? I'm looking to spend $500-$700 on this.

Yes they will fit. No you won't be able to get the parts or if you do get lucky enough to get them you will spend more than $700.

Almost finished with my first build and I have around $630 in it, so you can keep it in your price range
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