I just realised I have misled everyone. I meant retailers and manufacturers! They all seem to be making AR-9s with those weird angled stick mags and this confuses and frightens me.
oh that, that is just following on from the trend in real gun owners in the US running PCC (Pistol caliber carbines) in competitions as the ammo is cheaper and recoil less=faster shot times - TBH they should just run .22LR and be done with it ? But maybe that isn't manly enough....