Are you asking about the Reaper launchers?
Unfortunately, right now the only way to get them is to buy the whole CAV.
They've been saying they'll "fix" the CAV section of the store for a few years now, but they recently stopped selling all bits.
They're supposed to come back when the webstore gets revamped SOONTM.
I think I saw on their forums that it will be sometime in July when they start putting the Bones CAV models in the store, but I have no idea when the Gnomic will be added. They tend to add 50-ish items to the store at a time after fulfilling a Kickstarter.