From The Manufacturer/Wikipedia/People Smarter Than Us:
FN SPR™ (Special Police Rifles) are based on the legendary Pre-‘64 Model 70-style action with a massive external claw extractor for Controlled Round Feed (CRF), blade ejection, the original two-lever trigger and a three-position safety. All models have cold hammer-forged MIL-SPEC barrels with chrome-lined bores and are held to a +/- .001” headspace to produce and maintain one minute-of-angle (1 MOA) accuracy, making them natural choices for long-range target shooting and competition. A one-piece steel MIL-STD 1913 rail with an additional 20 MOA of elevation is factory installed. SPR™ rifles are fitted into matte black McMillan™ fiberglass stocks. Both cheekpiece height and length-of-pull are fully adjustable on FN SPR™ A5M models.