Taken in the context of illegal possession of such weapons and ammo, as is the point of the bulletin, that is a large cache and should be a cause for concern.
The bulletin notes that legal/Constitutional possession is not to be used as grounds for reporting of a "cache" or suspected terrorist activity.
True, but you're relying on the agencies noted to determine "innocent behaviors". It's a matter of trust. How much faith and trust do you put in those in these agencies?