If you don't need a complete AR-15 carbine and already have a mil-spec lower receiver, then an Olympic Arms pistol cal upper conversion unit is all you need. Our upper conversion units, along with your mil-spec lower will allow you to shoot 9mm, 10mm, 40 S&W or 45 ACP.

No modifications to the lower receiver and no tools are needed to install the unit. Just put the upper on your complete lower and you're good to go.

These top end assemblies use modified Sten or Uzi magazines. The mags have metal flanges welded to them so they mimic the shape of a standard AR-15 magazine and fit directly into the lower receiver. Our pistol cal units don't use mag well inserts. The magazines are all metal for rugged durability.

These pistol cal upper conversion units are fully assembled, headspaced and test-fired.

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