Have to agree with prairie goat on his assessment of the 204.
One way to gauge a cartridges popularity is to see where it sets on the amount of loading dies being sold for it. It takes a little searching on google but there is a listing of the most popular RCBS dies and the 204 is way down on the list whereas the 223 is still near the top. A few years ago when it was the latest fad it was nearer the top but now it has fallen way down the list.
drover
223 Rem, my favorite cartridge - you can't argue with truckloads of dead PD's and gophers.
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