To add to this - it’s modular because there’s a US military specification for it. As long as parts are to spec, they’re interchangeable. If I wreck my barrel, any AR-15 barrel (…that uses the same length of gas system…) should bolt on to my receiver. If I break my bolt carrier, any bold carrier should work. If the length of pull on a fixed stock isn’t good, I can get an adjustable stock.
‘Building’ an AR-15 from parts is only slightly harder and more expensive than building Star Wars Lego ™ kits. A bod-standard milspec AR-15 that’s reliable and accurate enough (3 MOA) can be had for about $450.
And, BTW, @Schadrach is absolutely right about it being a common hunting rifle. .223 Rem is commonly used for medium sized game and varmints; it’s commonly used for coyotes and feral pigs, and some people (depending on your state) use it for deer with heavier, 70-odd grain bullets.
To add to this - it’s modular because there’s a US military specification for it. As long as parts are to spec, they’re interchangeable. If I wreck my barrel, any AR-15 barrel (…that uses the same length of gas system…) should bolt on to my receiver. If I break my bolt carrier, any bold carrier should work. If the length of pull on a fixed stock isn’t good, I can get an adjustable stock.
‘Building’ an AR-15 from parts is only slightly harder and more expensive than building Star Wars Lego ™ kits. A bod-standard milspec AR-15 that’s reliable and accurate enough (3 MOA) can be had for about $450.
And, BTW, @Schadrach is absolutely right about it being a common hunting rifle. .223 Rem is commonly used for medium sized game and varmints; it’s commonly used for coyotes and feral pigs, and some people (depending on your state) use it for deer with heavier, 70-odd grain bullets.