VoHSAR Progression

From the original rifle of the post-Reformation Vanguard to its latest iteration, here are all the rifles in the VoHSAR family of small arms.
Mk1 VoHSAR
Heavily derived from the SCAR series of rifles(and is effectively their direct successor), the Mk1 VoHSAR was modified to accept higher caliber ammunition to better combat SEN forces. While a functional and mechanically reliable rifle, as times progressed it started to become somewhat obsolete, and was soon phased out. The Mk1 is virtually unseen in the current 4300s, and only exists as a rare collectors item.
Mk2 VoHSAR
The replacement for the outdated Mk1, the Mk2 possessed an integrated self-calibrating digital gunsight and a larger magazine capacity, and was more effective over longer distances. While a functional and able replacement for the Mk1, the Mk2's gunsight was known to suffer in humid and extremely cold environs, and would sometimes get confused by microgravity. Still, the Mk2 was used by mainline Vanguard forces for nearly a century before being replaced. The Mk2 VoHSAR is used by some training bases, and as a hunting rifle. A modernised version of the digital gunsight is available as a mountable addition that works with most current Vanguard rifles.
Mk3 VoHSAR
This gun is often seen as the first 'true' VoHSAR, and despite being around 300 years old many Marines still swear by it, and updated versions are still available for use. The Mk3 had a full electronics suite, allowing for an ammo counter, compass, mini-map, nav waypoint arrow, IFF indicator and smart-aim system, a forerunner to the neural-assisted targeting system the Mk5 now employs, as well as space for Marines to program their own software for the system(a fair few Marines were known for programming minigames onto the Mk3 they would play in their free time, the only rifle that would allow for this). While a competent rifle even 300 years after its original creation, the Mk3 was and is known to be a heavy and somewhat cumbersome weapon.
Mk4 VoHSAR
This rifle, an attempt at a VoHSAR intended as a close range rapid assault weapon over the heavy battle rifle style the VoHSAR usually follows, only saw about 2-3 years of service before being hastily replaced by the Mk4.5. The Mk4 had an extreme fire rate, enough so the weapon could intimidate Mantexx forces. However, the Mk4 had an extremely high jam rate, needed to be reloaded twice for effective use(the magazine itself and the coolant tank) and the recoil was incredibly hard to control. Nobody has forgotten the Mk4, but not for any good reasons.
Mk4.5 VoHSAR
The hasty replacement for the Mk4, the Mk4.5 replaced the receiver mechanics and barrel with that of the Mk3, doing away with the coolant tank entirely. The rifle was surprisingly functional and well loved by every Marine that uses it, and was used for close to 200 years before the Mk5 was developed. Even so, many Marines continue to use it as the Mk5 is steadily phased in.
Mk5 VoHSAR
The Mk5 is an attempt to recreate the advanced capabilities of the Mk3 on a more portable, updated form. The Mk5 possesses a photonics-based computer, making it faster and more efficient. The Mk5 possesses an advanced neurally assisted smart-targeting system, basing targeting information off the user's own knowledge if provided, allowing the weapon and its smart rounds to pick out and fire on weak points conventional sensors would be unable to. The Mk5 also increases its muzzle velocity with a gauss coil array around the body of the barrel. The Mk5 has not seen much use yet, but every engagement involving the rifle in significant number has proven its ability and carved its place in the Vanguard arsenal for decades to come.