So you are assuming this rifle has no other application than in war, right?
I really don't understand the big deal here.
The problem? You don't see it?
No matter how you define bioagents, the official definition is that of a weapon. No weapon designer or researcher in their right mind would include it as 'potential use'. It would immediately classify the weapon as being part of outlawed weaponry.
And it doesn't matter what it will be used for in the end, what matters is that someone expected it to be used for war, and possibly for dispersal of outlawed agents.
How can the US army confront terror countries because of their bio and chemical weapons, if they are cosnidering their own?