The FPX-15 uses the 7075-T6 forgings common to most AR15 rifles, and is completely compatible with all Mil-spec parts.
The FPX lower has added features including:
- A setscrew to lock the lower to sloppy mil-spec uppers.
- An adjustment screw to adjust the trigger (gunsmith option)
- The receivers are much better than plain Jane milspec. They are very precise to meet OUR needs.