be delivered in 2017, half of the order delivered by 2022, and the order fulfilled by 2028. The first batch of 400 rifles was delivered on 3 May 2017. The HK416 was one of the weapons displayed to U.S. Army officials during an invitation-only Industry Day on 13 November 2008. The goal of the Industry Day was to review current carbine technology prior to writing formal requirements for a future replacement for the M4 carbine. The HK416 was then an entry in the Individual Carbine competition to replace the M4. The weapon submitted was known as the HK416 A5. The Individual Carbine competition was cancelled before a winning weapon was chosen. Variants HK416 The HK416 chambered for 5.56×45mm NATO is offered in multiple barrel lengths available to the military and law enforcement market only. D10RS: sub-compact with a 264 mm (10.4 in) barrel D14.5RS (D145RS): carbine 368 mm (14.5 in) barrel D16.5RS (D165RS): rifle with 419 mm (16.5 in) barrel D20RS: full-sized rifle 508 mm (20 in) barrel The HK416C "C" for Compact is an ultra-compact version that only remained as a prototype and never went to full production. It has a barrel and is expected to produce muzzle velocities of approximately . It was submitted for the Ultra Compact Individual Weapon contract but lost to the LWRC M6A2. The M27 Infantry Automatic Rifle is a squad automatic weapon variant developed from the D16.5RS, adopted in 2011 by the United States Marine Corps. In 2018 the USMC decided to adopt the M27 IAR as their infantry standard service rifle. HK416 A5 The HK416 A5 is an improved variant that was first seen in the Individual Carbine competition. It features a stock similar to that of the G28 designated marksman rifle, except slimmer and non-adjustable. The rifle features an improved tool-less adjustable gas regulator for suppressor use, which can accommodate barrel lengths down to without modifications. It also features a redesigned lower receiver with ambidextrous fire controls, optimised magazine and ammunition compatibility, a repair kit housed inside the pistol grip, and a Flat Dark Earth color scheme. The stock has a fixed buttplate and no longer has a storage space, as well as the sling loops removed from it. The V2 HK Battle grip is incorporated, which has the V2 grip profile with the storage compartment of the V1 grip for tools. The handguard uses a new hexagonal-shaped cross bolt that