Long Arm of Marston

Long Arm of Marston is a gameplay achievement for Red Dead Redemption. The official description of the achievement is: "Kill 500 enemies with any rifle, repeater, or shotgun in any game mode."

Tips and Tricks
The following weapons can be used to complete this achievement:

Rifles

 * Buffalo Rifle
 * Evans Repeating Rifle
 * Repeater Carbine
 * 1860 Henry Rifle
 * Carnaco Rifle
 * Winchester Repeater Model 1873
 * Winchester 1892 Saddle Ring Carbine
 * Remington No.1 Rolling Block Sporting Rifle with Malcolm Scope
 * 1873 Trapdoor Springfield Cavalry Carbine

Shotguns

 * Browning Auto 5
 * Sawed Off Shotgun
 * Side by Side Shotgun (Double Barrel)
 * Winchester Model 1897

Other Achievements
This achievement can be completed in conjunction with:
 * Bullseye: Get 250 headshots in any game mode.