OSA Basic Upper Parts Kit
The OSA Basic Upper Parts Kit includes the essential components needed to complete a standard AR-15 upper receiver. Made in the USA, this kit offers dependable mil-spec functionality with one small improvement that can make your assembly considerably less frustrating.
Our “Stress-Free” ejection port cover rod replaces the traditional C-clip design with an expanded, knurled end. Instead of chasing a tiny clip across the garage, simply push the rod into place and give it a quick twist to secure it.
Save your Saturdays for building rifles—not searching the floor for missing hardware.
Includes
- Forward Assist with Pinned Cap
- Forward Assist Roll Pin
- Forward Assist Spring
- Ejection Port Cover
- Stress-Free Knurled Ejection Port Cover Rod
- Ejection Port Cover Spring
Features
- Made in the USA
- Compatible with standard AR-15 upper receivers
- Complete forward-assist and ejection-port-cover components
- Clip-free ejection port cover rod
- Simple push-and-twist installation
- Dependable option for new builds or replacement parts
Our Thoughts
Upper receiver parts are simple—until a tiny C-clip launches across your garage and disappears forever.
The OSA Basic UPK eliminates one of the most annoying parts of assembling an AR upper. Its knurled ejection port cover rod secures without a separate clip, making installation faster and reducing the chance of losing small hardware.
This kit may not have the billet components or upgraded controls found in our OSA Premium Upper Parts Kit, but that is not its purpose. The Basic UPK is designed to provide reliable, straightforward parts at an affordable price.
For a dependable mil-spec build without unnecessary extras—or unnecessary frustration—the OSA Basic Upper Parts Kit gets the job done.
