One of each of course. One way to avoid the chamber lotto for the Swede is to specify a 6.5x55 SKAN reamer. This was Sweden's attempt to re-standardize the dimensions and to allow for 140 grain +p loading. The dies can be more expensive though and harder to find. But a real loony would go custom or at least mix and match about three different makes of dies plus ream the seater when the rifle was chambered.
Choice is easy short action Creedmoor long action Swede. My 6.5x55 is doing things it is not supposed to with Reloder 26 and 142 NLRAB or 140 Bergers at 2900 fps. I will have to see how long the brass holds up but with Lapua brass it can handle some enthusiastic charges for awhile. No need for a 6.5x284 or 06 but the 6.5x06AI is still tempting.
But the quintessential loony round IMHO is the .256 Newton.
"When you disarm the people, you commence to offend them and show that you distrust them either through cowardice or lack of confidence, and both of these opinions generate hatred." Niccolo Machiavelli
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