Today my mind kept wandering back to these holes......

https://www.globalcastingmagazine.co...nkage-defects/

While reading the link I read this.

"Heavy shrink-prone areas can be chilled in a number of ways. Figure 5 shows holes drilled into the cores and the subsequent cooling pins cast during mold filling. These iron pins serve as radiators to transfer heat from the casting into the sand more rapidly, to avoid shrinkage in those areas. In some cases, pins or fins can be added to a pattern."


Of course in the article they are not talking about wedge casting.