Boiling longer seems like a decent option. Once I can afford more propane I will try that, along with a longer boil on the bone. That will usually soften anything else. Man these birds were tough lol. They were tough in the way the acted too lol.
looks like a grinder is in order for us.
The trick is also to simmer gently rather than boil furiously
yea i did that on the 3 hour boil