OSA Basic Lower Parts Kit (LPK)
The OSA Basic Lower Parts Kit is designed for builders who want dependable, American-made quality without paying for features they don't need. Manufactured in the USA by Schmid Tool—one of the industry's most respected OEM manufacturers—this kit includes everything needed to complete your AR-15 lower receiver, along with our Elite 3.5 lb Two-Stage Trigger for a crisp, refined trigger pull right out of the box.
Whether you're assembling your first rifle or building a reliable duty or range gun, this kit delivers proven performance at an exceptional value.
Includes
- OSA Elite 3.5 lb Two-Stage Trigger
- Pivot & Takedown Pins
- Pivot & Takedown Pin Springs
- Pivot & Takedown Pin Detents
- Ambidextrous Safety Selector (Long/Short Levers)
- Safety Selector Spring
- Safety Selector Detent
- Magazine Catch
- Magazine Catch Spring
- Magazine Release Button
- Bolt Catch
- Bolt Catch Spring
- Bolt Catch Plunger
- Bolt Catch Roll Pin
- Buffer Retainer
- Buffer Retainer Spring
- Trigger Guard
- Trigger Guard Roll Pin
Features
- Manufactured in the USA by Schmid Tool
- Includes OSA Elite 3.5 lb Two-Stage Trigger
- Ambidextrous safety selector with long and short levers
- Complete lower receiver parts kit
- Mil-spec compatibility
- Excellent value for new builds and replacements
- Compatible with standard AR-15 lower receivers
Our Thoughts
Not every rifle needs a premium collection of boutique controls.
Sometimes you just want quality parts that work—and work well.
That's exactly what this kit delivers.
Manufactured by Schmid Tool, the same company responsible for producing OEM parts for many of the biggest names in the firearms industry, this kit offers dependable quality without unnecessary extras.
The biggest upgrade over a traditional mil-spec lower parts kit is the included OSA Elite 3.5 lb Two-Stage Trigger.
Instead of the heavy, gritty trigger commonly found in standard kits, our Elite trigger provides a smooth first stage followed by a crisp, predictable break that improves both accuracy and overall shootability.
Another feature we appreciate is the included ambidextrous safety selector with both long and short levers, allowing shooters to configure the rifle to their preferred setup right out of the box.
For most AR-15 builds, this kit strikes an excellent balance between affordability and performance.
Basic vs. Premium
The OSA Basic LPK is ideal for shooters looking for proven mil-spec reliability with a significant trigger upgrade.
If you're looking for enhanced controls, billet components, and premium hardware from Forward Controls Design, our OSA Premium Lower Parts Kit is the next step up.
Final Verdict
The OSA Basic Lower Parts Kit provides everything you need to complete an AR-15 lower receiver using high-quality, American-made components from Schmid Tool, while adding an excellent 3.5 lb two-stage trigger and ambidextrous safety selector that outperform standard mil-spec parts.
If you're looking for a dependable lower parts kit that offers premium performance where it matters most without breaking the bank, the OSA Basic LPK is an outstanding choice.
