Search:

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

https://www.globalcastingmagazine.com/index.php/2013/10/25/7-ways-to-avoid-shrinkage-defects/

While reading the link I read this.
...

And learn.

Our "modern" thoughts and ways" influence us in understanding them and their ways.

Our ancestors were not idiots.

There is a reason why things were done even though we might not see it.

Wouldn't you use the sides of the mold to control the depth?

If you put a longer peg in the middle of the mold it would open up the sides and allow flash until to much would just be a leak.

The main trouble I see with the steel peg idea is that every time you hit the peg you would make is slightly shorter.

Depending on the abrasive you used and the material of the peg.

Maybe they...

Just thinking out loud I can think of a couple of possible reasons for the extra or larger holes.

If the holes were made of expensive metal the holes would save material costs.

The other reason...