After spending nearly 5 million glimmer on the gunsmith blue mods purchase, I am convinced that there is no chance that I will have Solar arms or chest grenade mods drop. Is the drop rate seriously that low or is something broken for these particular mods?
You're better off trying to craft your own. Even with the half-ass craft system... I wish you could craft the mods you wanted... but that would imply Bungie wants to give us player choice... and we all know Bungie doesn't want that.