I'm at the end of my first Call hatch right now but I got great advice from my friend who gave me the eggs who hatches hundreds of them a year and I'll pass what she said on to you. It's working really well for me.
Hand turning is best for them, unless you have a turner like in a
Brinsea Octagon that just rocks them from side to side - my
Brinsea is doing really well with them and it was kind of an experiment to see if they'd tolerate it but they have. I wouldn't use any turners that hold them upright, they tend to die late in incubation if you do that, according to those that have tried it. Hand turn at least three times a day, more if you can.
Keep the humidity low, around 30%. That's been working for me and it's what works for everyone else I've spoken to that hatches Calls regularly, and is what my friend suggested to me to use. So far it's working perfectly.
For temperature, Calls actually do best at a little hotter than normal, 100.5 degrees instead of 99.5. If you can only do them at 99.5, that's fine, they'll still do okay.
At around Day 17, it benefits them to do some misting. Do it once a day for at least 2 days, longer if the air cells are looking small. It cuts down on gooey, sticky hatches.
Lockdown is on day 23 since they hatch on day 26. You want to watch them at this point for drawdown and internal pip. At that point you can give them 24 hours from time of internal pip to external pip. If they don't pip in that time period, it's time to make a safety hole for air. Just a tiny safety hole at the top of the air cell that will let air in. You make it with a small screw or drill bit. Gently but firmly place it against the shell and twist it back and forth until you're through the shell and the membrane.
From there, wait another 24 hours for them to externally pip. If at that point there's still nothing, it's time to open up the air cell. Lube the inner membrane with something such as coconut oil or neosporin to keep it moist. Watch for receding veins and a yawning movement - yawning means they're still absorbing the yolk. When it's ready to hatch it'll start struggling.
Calls are difficult to hatch and often need assisting, so be prepared to do what I detailed above.
My batch just went into lockdown, so I'm getting geared up to start helping when necessary. Luckily I'm a hands on hatcher, so I've had plenty of practice
