It is a beautiful gun, with awesome animations yet nobody uses it because of the stats.
But if AH wanted to they could just (through the editing of what is probably 2 lines in a .json file) give this gun a reason to exist.
Make it AP 4 and bump up the damage (similar to what should happen to the Deadeye).
What would be more thematic than using a rifle that:
"It is traditionally gifted to every citizen upon turning 16 to encourage service"
The lore writes itself, just make up a reason, like helldivers where bringing this from home due to the sentimental value and they where getting slaughtered on mass, so Super Earth just gave them +p+ bullets.
Yet they will probably not do that because "It is a challenge gun, it's not supposed to be good". So nobody uses it.