You can swap out barrels to whatever caliber you want. However, you have to be sure you're getting the same make of barrel.
I called AOA this morning to find out what was available. I want a .22 cal barrel and mags. I got mine in 2023. They changed barrel manufacturers sometime after that. They didn't have any of my make. They said try back next month.
It's a simple mod, requires only a couple of metric Allen keys. AOA has a youtube video on it, they say to make it all the way up, hand tight, then back it out ⅛ turn, then tighten the 2 barrel clamps.
When I followed those instructions, I couldn't load my magazines because the barrel came into the magazine well too far. For me, it was more like ⅜, but idk if that's because I've got the earlier barrel..