You will have to take that up with the two local shops who told me the story, and after they told me I began looking as I went from store to store in search of ammo - No Powders on the shelf.
As for "No track record....", not so, just no record of them detonating any but there IS record of them being caught with "pipes" and "powder"; at least here on the left coast (and I think there was a report somewhere mid-west during a traffic stop)
As for BLM/Antifa being two different groups; yes they are. But in some areas (left coast) they do tend to intermingle. I can tell you that from the Nevada innocent when we (yes, me and 1500 other local residents) physically chased a group of BLM out of town. There was, I saw and read myself, Interner dialog going between them. That first weekend was to be the "Small test protest" with a "Main protest" the following weekend when Antifa out of Las Vegas and Arizona stated they would join in.
However, after their 'warm' reception the first weekend with 1500 (some reports said 2000) armed citizens, local militia, even Grandmas and Grandpas sitting on their porches displaying....the second week remained quiet, however the neighbors remained patrolled for the following few weeks.
However, three or four of the BLM ones did return about a month later, two shot a Sheriff in the face, both now serving time, at least one other weeks later was in the news having been arrested (forget details on that one) - I recognized their faces as having all been involved in the first incident.