Wrinkled bullets, or bullets with dull edges on the base or lube grooves is usually caused by the mold blocks not being hot enough or that oil or a lubricant has gotten into the bullet cavity. Fill your melting pot right to the top with lead, when the lead is molten, dip the corner of the mold (the aluminum part) into the lead for at least 30 seconds.
A good indicator of mold temperature is the puddle that forms on top of the sprue cutter as the mold fills. If this puddle solidifies as you fill the mold, the lead inside is doing the same thing, resulting in wrinkled bullets. It should stay molten for 3 to 5 seconds after the mold fills and you stop pouring. Also make sure that the mold cavities are clean (we use Coleman lantern fuel as a solvent), and smoked.