I modified an old Lee mold to make a bullet for my Snider (0.588" groove diameter). I drilled out an old Lee Mold (I used a 9mm double mold) with a 37/64" drill (0.578"). I then tapped the mold a 5/8" (0.625") NC bottoming tap. This created sharply pointed grooves to a 0.625" depth in the mold, which translate into bullets with 0.578" grooves and a 0.625" O/D. I sized them to 0.590", which was not difficult.
The bullet had a "spiral" lube groove which held enough lube for the low pressures I employed.