BlackMZ was over 80gr by weight for 100gr by volume. So was Shockeys. Who knows what their latest attempt weighs. Triple7 weighs even less and makes better velocity but is not as easy to ignite. Other than a plinking powder when its cheap i just dont see any reason to try the latest flavor. I dont own a side lock or cap and ball revolver. Triple7 ignites just fine in a modern inline with percussion caps and cost about the same. The crud ring is not nearly as bad with #11 caps.
Since you referenced FG, here is a quote from him.
You are right. The Black MZ is not consistent at all in granulation and that's why you will see quite a bit of variance in velocity spread over the chronograph.
