I just finished an amazing AR10 build. Six thousand dollars. Now I have to build an AR15 on a budget. Budget is $850. Requirements are: .556 cartridge, 16" barrel and 1 MOAish. M-lok freefloat handguard, and $150-200 for optic. Not much else matters. Can have crappy trigger, buttstock, pistol grip. Doesn't matter. Any suggestions are appreciated. Must be 1 MOAish. 1.5 maybe, but not 2. What do I shop for? Can be a complete rifle, upper and lower, or put together from pieces. Whatever gets the most bang for the buck.