Threshold Effects in Charm Hadroproduction

We describe calculations of $c \bar c$ production to next-to-next-to-leading order (NNLO) and next-to-next-to-leading logarithm (NNLL) near threshold in $pp$ and $\pi^- p$ interactions. We study the relevance of these calculations for existing $c \bar c$ total cross section data by examining their sensitivity to partonic threshold kinematics, their convergence properties and scale dependence.