Rifle Ammo. 458 socom ammo. SBR Ammunition 458 SOCOM 350 Grain Soft Point 500 rounds. $ 520.00. Category: 458 socom ammo. Description. Reviews (0) Description. SBR is one of the first manufacturers to offer loaded ammunition for the exciting new 458 SOCOM round, offering several different and potent loads for practice, hunting or defense. 458 .... SBR Ammunition 458 SOCOM 400 Grain JSP (20 Rounds) - SL45857. From the manufacturer: SBR is a manufacturer of small arms ammunition specializing in precision Training, Match, & Duty cartridges to support Law Enforcement, Government, Military and Civilian customers.