Ruger AR-15 Assembled Upper Receiver

Ruger's AR upper receiver in assembled form, held to the same standard as the receivers that go out on their factory rifles. It follows AR-15 pattern dimensions, so it pairs with mil spec components from the rest of the market.

Ruger is direct about the caveat that comes with any component sale: with the sheer number of AR parts in circulation, no manufacturer can promise fit with every part out there, and they recommend a gunsmith handle the assembly work. That is sound advice for anyone building rather than buying complete, and it matters most on a first build.