This powder is CSB-1M, like CSB-1 but with a slightly smaller flake. CSB-1 is reportedly what the ill-fated / Expansion Industries ETR-7 powder was, rebranded.
Recently I discovered that Hi-Tech Ammo was reselling CSB-1M and has a good supply. I spoke with the owner and got 1 lb powder for evaluation. I worked up a load and shot a pound's worth - basically just like CSB-1/ETR-1 but the smaller flake might meter even better. This is a high bar as the bigger flakes already meter extremely well.
Short version: Fast Powder, Meters Well, Good Fill Volume, Temperature Stable, Burns Clean, Great Price.
Availability - Just Hi-Tech Ammo - for now.
I have no reservations about this powder.
My last load workup:
124gr ACME New Nose Profile polymer coated, < 1.130 COAL, 3.8 gr CSB-1M, 128 Power Factor
Here are some old threads on ETR-7:
http://www.doodieproject.com/index.p...etr-7/?hl=etr7
http://www.doodieproject.com/index.p...ition-powders/