Holy cow... an opportunity to finally put that fluid mechanics they made me learn to use...
Is this a K baffle design? Could it be line bored to get the thing concentric? And you could possibly add a good sized 45 degree "countersink" at the entrance side of each of the first few baffles. Of course, that brings up the whole converging/diverging nozzle problem with super sonic flow... which is what the K baffle design mitigates, sort of.