https://www.colt.com/detail-page/colt-infantry-automatic-rifle-iar This is a very unique firearm as it is one of 200 ever produced AFAIK. A complete military standard Colt heavy barrel MONOLITHIC upper on a Colt M4 semi auto lower receiver re-engraved with "IAR". Folding top notch quality front and rear sights. Government money-is-no-object. The original full auto lowers were destroyed except those sold and issued the the Mexican military because H+K won the IAR contract. MANY people thought Colt should have won including those in the know. It is what it is. Factory folding sights included as well as the steel reinforced specific front vertical grip which doubles as a bipod. Rear stock is special VLTOR heavy duty and factory. Internals are factory Colt as is the charging handle, bolt and carrier. . The last variant I know of sold for 4.5K before all this CV stuff. https://www.gunspot.com/listings/archived/2103/rare-colt-m4le-iar-556mm-semi-automatic-rifle/ $4,000 includes all Colt parts. No tax but you pay for shipping. With a Fostech ARII binary trigger this may as well be a light squad machine gun just as it was designed to be. Completely legal in most states. These will be appreciated and collectible in the future as well as shoot-able today. Colt 9MM DOE uppers were <1K a few years ago. Now Complete semi guns have an 8K ask. These IARs are more rare and you get a complete rifle. Just check out the price for real Colt lowers. Wanna geek out ? PS 5.56 Belt feds vs BIG mag feds like a Surefire 60/100 or Magpul 60 round mags makes belt feds cumbersome and obsolete and IMO.