The axial velocity in two different tests with pulse-jet bag filters made of needle felts on a pilot-scale test facility separating limestone dust from air under ambient conditions is measured and simulated at different cake area loads. Results reveal that the axial velocity profiles are not truly linear along the whole length of the bag. A nonuniform gas flow prevails when the bags are differently dust-loaded. The same behaviors are observed even at the end of filtration cycles at different upper pressure drop limits. At the higher upper limit, the nonuniformity is stronger. Radial velocity profiles are nearly symmetric along the length of the bag.