I am replacing the barrel on an old small frame colt revolver . Unfortunately the colt threads are tapered. The old barrel threads are 32 tpi and the thread OD ranges from 0.438" to 0.445" over 1/2" The new replacement barrel is also 32 tpi and the threads range from 0.444" to 0.450" OD over 1/2" length. So the new barrel screws in all the way but for about 1/4", by hand. It is much tighter than the original barrel which is loose up to the last 1/4 turn. Forcing the new barrel in isn't an option, it's brand new, old stock, and nickel plated. Does anyone have any ideas about how to chase the threads on the new barrel? I haven't found a die (or a tap) this size so far. It's a bit bigger than 7/16X32 and tapered!