Army .69 Cal Buck and Ball
Fort Fillmore, New Mexico
1851 - 1861
 
The Armies deadliest shot, as .69 Cal and smaller round ball wrapped in a paper cartridge. These were discovered in the 1960's in a buried cache by metal detectorist, near present Fort Fillmore, New Mexico, built in 1851 to defend settlers and travelers heading to the California gold fields from attacking Native Warriors. This bullet was retired by the army in 1869.
 
- Fort Fillmore 
Fort Fillmore, located at 32°13′30″N 106°42′52″W, was a United States military fortification established by Colonel Edwin Vose Sumner in September 1851 near Mesilla in what is now New Mexico, primarily for the purpose of protecting settlers and traders traveling to California. Early frontier migrants were under constant threat from attack by local Native Americans, and a network of forts was eventually created by the U.S. government to protect and encourage westward expansion. Fort Fillmore was intended to protect a corridor plagued by hostile Apaches, where several migration routes converged between El Paso and Tucson to take advantage of Apache Pass.