I've been meaning to do a study of the SA-02 for quite some time, finally sat down and did it :U
also my horrible hand writing U:

Being rugged, reliable and capable, the SA-02 is the standard issue assault rifle of the Ascendancy military. 

In direct response to the short comings and inadequacy of the old SA-01, a 5.45x39mm assault rifle based off and old Straxian Empire design used since the inception of the Ascendancy, the SA-02 was created to address the flaws exposed during the skirmishes on Hellion V and Strax's moons. 

Because of the shortcomings of the SA-01, the Grand General put out an order to develop a replacement; Strak Arms and Volk Design Bureau got to work on competing designs, the SA-02 being their first 'contract' for the very young Strax Ascendancy. Eventually, the Strak Arms design won out and became the SA-02. 

Made in several different variants, the standard version of the SA-02 mounts a built in, underslung, 12-gauge shotgun. A grenadier version of the rifle, replacing the shotgun with a 40mm grenade launcher, was swiftly created and a carbine version, which removes the underslung weapon and shortens it in its entirety, followed quickly afterwards for issue to command crew. 

With its larger 7.62x54 round compared to the SA-01, the SA-02 proved to be well worth the effort and time invested into its creation. As the rifle is a blend of an assault rifle and battle rifle, it functions well as a jack of all trades weapon at most ranges. Moreover, the underslung shotgun gives added versatility, making the weapon excellent for confined spaces, especially with its rifled barrel allowing for the use of specialized munitions such as frag canister shells.

On the topic of the Tround, https://youtu.be/MTh0EMAH99A?t=4s 
Something unique and different which is what I wanted for the SA c: