Saige, this rifle uses the highly customizable AR platform. Other than barrel and magazine caliber differences, all other mil-spec parts are standard AR interchangeable. Stocks, hand guards, accessories, scopes etc are all the same. Cheers and stay safe!

Another thing, most people like to change out the trigger. Instead of spending $100 plus on a drop in trigger, Google ( JP Enterprises Trigger Spring Kit AR-15 ) it is a spring kit that works with your original milspec trigger that drastically lightens the pull weight for around $10. You can also polish the trigger Wich helps alot. Hope this helps.

Saige, yes most ar15 parts are interchangeable. For the stock you have two different sizes, you want a milspec stock, not commercial. For the handguard any free float handguard will work. Other than that most milspec AR-15 parts will work. That's how I learned how to build ars, I bought one and just started replacing parts. Next thing I knew I pretty much changed the entire rifle and had enough spare parts to make a second rifle. Hope this helps and if you have any more questions feel free to ask.