Another brainchild of Layne Simpson, the .358 STA is an 8mm Remington Magnum case necked up to accept .358 Caliber bullets with the shoulder angle changed from 25 degrees to 35 degrees and body taper removed to maximize powder capacity. Able to propel a 300 grain bullet at over 2700 feet per second for 4,900 ft.-lbs. of energy, the .358 STA is a formidable big game cartridge. It has never emerged as a production cartridge and has had very limited success as a wildcat, overshadowed by the more popular .375 caliber commercial and custom cartridges.