With my Redding BR-30 I've found I need to "slow dump" the charges of 4166 else it will occasionally bridge. The kernels are short cut, but they're fatter than 4895, Varget, RL15 and the like. I think their shape allows them to pack in just the right way to hang up in my measure.
Even though 4064 is much crunchier in operation, I've thrown thousands of charges and never had it bridge.
