For which type of ordinance is 2 blocks of M112 consistently used?

The M112 is specifically known for being a type of explosive charge used within various artillery systems, particularly associated with larger caliber munitions. In this context, when we consider the reference to "African 155mm," it is clear that the M112 charge is often utilized in conjunction with artillery shells like the 155mm howitzer rounds, which are standard in many military arsenals globally, including those in Africa.

The correct focus on the 155mm artillery rounds aligns with how explosive charges such as the M112 provide the necessary detonation force to enhance the effectiveness of these larger munitions. Using two blocks of M112 ensures the charge is sufficiently powerful for such high-caliber artillery applications, which require careful handling and specific charge configurations to optimize their effects on the battlefield.

Other options, such as rockets or small ordnance like hand grenades, typically use different charge types or configurations, making them less relevant in this context. The M112 is primarily tailored for deployment in large explosive systems rather than the smaller or different categories listed in the other choices.