According to my research, the Nineball hicapa routers do not work well with single stack mags. Only the Guarder ones are specifically made for single stack mags, but they are hard to find.
This is how I shimmed my mags, I simply fabricated and placed the shims under the routers.
Red mag shimmed, blu stock
A comprehensive tutorial was uploaded by Lazouche a while ago, which is the one I followed.
Here it is:
http://m.youtube.com/watch?v=G4S2sspWmH4