2520 and BL-C(2) are both spherical propellants of the older formulation type with hard-to-ignite (relative to stick powders) deterrent coatings that CCI reformulated their magnum rifle primer mix for in 1989. They generally require a magnum primer to ignite consistently.
In the early 90's I ran 2520 in my M1A for one year, but because I didn't know to try magnum primers with it back then, I found I had to deburr all may case flash holes to get it to behave up to stick powders. Even then, it didn't seem to be as good at different temperatures.
If I were looking at spherical propellants today, I'd probably look at the Ramshot line, as they claim to use more modern deterrent chemistry that doesn't require a magnum primer to light up well.
