5.56x45mm Federal Lake City FMJBT 55 Grain 20 Rounds .223 for Military Grade Rifles New Production FMJBT 20 Round box of this special 5.56 ammo, manufactured at the Lake City Arsenal, has a 55 grain boattail bullet with lead core and Lake City or Federal brass all designed for super accuracy in extreme conditions. 3165 fps. This is first quality, new production .223 ammo designed for Military grade rifles packed in a 20 round box, 25 boxes per case. Sold by the 20 Round box. Our Low Price: $8.00 Order Online: AMM-207 *Offer applies to Lake City XM193, FMJBT, 55 Grain, 20 Round Box Regular Price: $8.19 Offer valid from April 26-28 for purchases made online only at CheaperThanDirt.com, no back orders or rain checks.