But let's say scalling 308Win to 224 bullets would almost make 221 Fire Ball.
OK, I am guilty of looking at this more closely based on the original idea of scaling everything to do with a cartridge...length, diameter and bullet diameter.
A 6.5x45 (223 case) is an 86% scale of a 308 Win.
A 6.5 BR is a 91% scale model of a 6.5 WSSM.
A 260 Rem is a 94% scale model of a 284 Win.
Also a 7x45 (223 case) is almost an 86% scale of a 338 Federal.
A 6x45 (223 case) is an 86% scale of a 7mm-08.
A 20 Tactical (223x204) is almost an 86% scale model of the 243 Win.
A 223 Rem is almost a 70% scale model of a 30-06.
A 22 Hornet is almost a 70% (68.8% - 72.7%) scale model of the 30-30 Win.
A 327 Federal is an 87% scale model of the 357 Mag.
A group of 86% scale models and their parents, plus the 223 and 30-06 would be good caliber coverage I think.
Musings...