Early ARVs contained a secure safe between the seats containing a .38 Smith & Wesson Model 10 for each member , with two 9 mm Heckler & Koch MP5 semi-automatic carbines secured in the boot . After ARVs became established and the practice was accepted for widespread use , the Model 10 revolvers were replaced by the semi-automatic Glock 17 handgun chambered in 9 × 19 mm . In 2010 , the Heckler & Koch G36C 5.56 mm carbine was introduced in case of a Mumbai style terrorist attack
Mumbai style terrorist attack
2008 Mumbai attacks
Armed response vehicle