does this fall into the "if this was dangerous, people would have died of it back in the day" category?

Yup. Between the simmering, the straining and the further cooking, any amygdalin has been cooked off or denatured.

My mom always simmered chokecherries until they burst, stirred them around to mash them a bit, then hung them in a cloth bag to drain off the juice. it's hard to get any busted bits of pits out of the jelly

The only real threat info I have read is about apricots and peaches (apple seeds apparently pose no threat due to their casing) but nothing comes up on chokecherries.

I would assume the primary risk would be to children, the elderly, and those with compromised immune systems.

However insuring that the pits are not included in the end product is strongly recommended. Both methods you used involve a crushing mechanism as opposed to simply draining so for future reference I'd suggest sticking with one of the many draining.straining methods rather than any mechanical crushing.

JMO

Dave

Here is a link that might be useful: Previous discussion about this question

Thanks for the responses.

Dave, even in the foley mill it was just some pits splitting in half I noticed. Nothing or next nothing ended up in the finished product. With spoon and screen method no pits broke at all, so although a little more laborious I'll do it all that way next time.

I suspect I am being way over-cautious - even if some pit debris were included and thus some amygdalin, presumably one would have to eat a huge amount of jam at one time to get harmed?

Yes. Peaches are the worst, but even for them you can eat a few raw pits (they are very similar to almonds in shape and taste) with impunity.