On 19 Oct, 10:00, Matty F wrote:

The sample was cast.

Almost certainly gravity sand cast, by someone who knew what they're
doing, probably in greensand. Although it's even castable in an open
back mould, these were cast industrially by using a core (a separate
shaped lump of sand, laid into the mould after moulding and before
casting). If you're capable of doing cores at all, something like this
is easier to cast with an added core than it would be to use a hollow-
box pattern and to get clean pulls from the mould every time.

The big difference, in terms of pouring success, is that they'd
gravity cast it and use quite a deep mould box to do it in, with a big
pour. The inlet gate would be deep, so the pressure in the mould
cavity is high and you'd get good flow into the mould before it
chilled. Easy if you're tooled up to do deep moulds and handle the
excess material for a deep gate. Most of us though are handling small
crucibles and need every spoonful of the melt.