The 204 suffers from not being the primary design around the CZ, the Vixen, the Interarms, and the like, nor even the short Kimber 84; its MAX COAL is a bane for it and its parent cartridge with tipped and high B.C. secant ogives or those with both.
Their design parameters were around the 222, stretching it, the 223.
The 204 suffers the same fate as it parent cartridge in ARs as well unless different magazines are used with high B.C. bullets.
Also, the 204 was designed as a varmint cartridge and requires a throating modification for bullets beyond varmint bullets, which will exceed most 222/223 short bolt magazines.
The 22 Nosler was not.
