Description The 223 Rem 55-grain FMJ bullet has a lead core and copper-based gilding metal jacket. No steel means non-magnetic! The bulletâs hard jacket promotes optimal feeding and lower residue accumulation, and its cannelure wonât let recoil jerk it out of its even seating. Winchesterâs ballistically efficient 55 grain FMJ remains faster than Mach 2 until nearly 300 yards, so youâre sure to appreciate that flat trajectory which makes aiming that much easier. Backed by generations of legendary excellence, Winchester âUSA White Boxâ stands for consistent performance and outstanding value, offering high-quality ammunition to suit a wide range of hunterâs and shooterâs needs. Firearms, trailers, and some accessories are only available for purchase in stores. Each location follows all BATF and individual state/county/city laws to insure the desired product is legal for sale. Any info provided online is subject to change, please go to your local store for more accurate information.