Yes, the myth ive seen propagated extensively, leading to multiple HEATED debates, is that GA is absolutely the wrong drag law to use for slugs and G1 is wrong for pellets. In reality (actual shooting and mapping out trajectory curves relative to what ballistic apps predict), and as
@wolfmangreg commented, the trajectory curve (and the BCs) dont change enough to matter, whether using GA or G1.
The "GA for pellets and G1 for slugs and n'er the twain shall meet" crowd are dying on the hill of semantics. Academically and theoretically, sure GA for pellets and G1 for slugs. But in the real world of throwing lead downrange and wanting it to go to a very specific place, it simply doesn't make much of a difference.