What are the improvements in the VFC/Umarex HK M110 A1 Version 2023? REAPERs Airsoft tries to find out in this comprehensive video review. The Heckler & Koch HK M110 A1 is a high-quality airsoft rifle modeled after the US military service rifle. It features a 455 mm long precision barrel, ambidextrous controls, and universal accessory compatibility. The rifle also comes with a removable iron sight and a 5-stage collapsible stock that accommodates various batteries.