What Is A4 Armor?

A4 armor is Alpine Armoring’s handgun-rated protection level, equivalent to CEN BR4 and NIJ HG2. It stops handgun rounds up to .44 Magnum, including 9mm Luger and .357 Magnum, and is the standard specification for executives and private clients facing pistol-level attacks in urban environments. A4 does not stop rifle fire, which begins at higher levels.

• What A4 stops. A4 defeats .44 Remington Magnum at 1,430 feet per second (436 m/s), plus 9mm Luger and .357 Magnum, the handgun rounds behind most carjackings and street attacks. That places it in the handgun tier of the armor-level scale, below every rifle-rated level, and it also stops the smaller-caliber handguns rated below it, which cover most urban civilian incidents.
• The standards it maps to. A4 equals CEN BR4 and NIJ HG2, so a protection level quoted in either system points to the same build. As General Manager Dan Diana notes, fixing the risk first and the level second keeps clients from over-armoring or under-armoring.
• What it adds to the vehicle. A4 bullet-resistant glass runs about 19-21mm thick, close to a stock daily driver and far lighter than rifle-rated builds, though Alpine still tunes the suspension and brakes for the added weight.
• Who specifies A4. It is the practical choice for corporate executives, celebrities, and professionals in cities, from daily commutes to airport runs, where the realistic threat is handguns and discretion in an everyday armored sedan matters more than rifle defense.
• How Alpine Armoring verifies it. Alpine tests its vehicles at the United States Army’s Aberdeen Proving Ground and is the only manufacturer whose armored vehicles have passed both VPAM VR7 and Aberdeen requirements. To confirm whether A4 matches your threat profile or to compare it across Alpine Armoring’s armored vehicles, contact Alpine Armoring’s team.