Complex sentence: Among the most common sidearms are models produced by Glock, Smith & Wesson, SIG Sauer, and Beretta in either a 9mm,.40 S&W, or.45 ACP.
Split into simpler sentences: Among the most common sidearms are models produced by Glock, Smith & Wesson, SIG Sauer, and Beretta. One of these brands in either a 9mm,.40 S&W, or.45 ACP.