HB wrote:A Swiss engineer wouldn't dare leave behind holes as part of the casting process, so it's safe to assume they serve some useful purpose. I'll go for either (a) extending preinfusion, (b) reducing the puck temperature shock, or (c) both. Essentially I'm guessing that it's a poor man's expansion chamber, i.e., a space for the initial hot water to go, allowing the group a few extra seconds to stabilize without scorching the top of the puck.
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