If a single egg is rapidly popping multiple times, your MgAl is too fine. You can use a coarser material or try replacing part of the MgAl with more coarse. It is common to have to tune the eggs for your chemicals. If many rapid pops, it's too fine, and if it smolders without popping it's too coarse. This is assuming the other chemicals are sufficiently fine. I've had bismuth that was coarse and it caused problems.
Interesting, thank you.
Now, may I ask, how would you grind your Bismuth (if needed)?
I don't know the size of my Bismuth, I still haven't gotten all the chemicals needed to start "playing".
I was thinking, maybe in a ballmill. But then again, how to clean that ballmill completely after use? I have bad experiences with cleaning ballmills for metals; I ended up throwing out 2 of them. And now I hold on dearly to my last 2, and I'd prefer not to make anything but BP-ingredients in them.