Don't confuse PilotYip - he might think this is Kalitta Charters, flying the lears and Falcons...
Kalitta Air's business is international air cargo in their 11 (currently) 747 freighters. I'd say half the business is US Mail (mostly from US to the Gulf). A lot of the rest is general freight from Hong Kong and Korea to the US. Some military charter also. They are also starting flying from China to the US as well.
If Kalitta Air does ACMI, it's a very small part of the business - nothing compared to Atlas.
The company has 137 pilots on the senority list. That doesn't include the 75 flight engineers. Another class of 12 is scheduled to start in September.
iaflyer