You can bet that the MSM would downplay 1000 chemical shells being a stockpile. The fact that they found one is good enough for me. These nerve agents only require a drop to kill a person. There's plenty of "drops" in one shell. Taking the chemicals out of a shell and placing them in a more compact, portable bomb could do a lot of damage in a NY or DC subway station.
I dunno - by their own scale, a Ruger 10-22 and 1,000 rounds of ammunition is an arsenal.