Egypt finds another half-ton of explosives on way to Gaza

From Ma'an:

Egyptian security forces seized a cache of explosives in the Sinai Pensinsula on Sunday, security sources said.

...[O]fficers uncovered a weapons depot containing half a ton of TNT explosives and anti-aircraft shells. The ammunition was packaged in bags ready to be smuggled through underground tunnels into Gaza, sources said.

Given the number of caches Egypt has found, how many do you think they miss?