Here's a 1 ton explosion:
If we use 20 micrograms of Iron / Anti-Iron mix in a high impact force trigger in a simple bullet design, we can get 1 ton of TNT equivalent explosion.
We could have a easily mass producible Anti-Borg personnel weapon using primitive FireArms with updated technology. Have a Simple Tungsten Carbide Penetrator tip + Iron/Anti-Iron explosive payload + lead to encase the rest for the bullet in a polymer coating using a very aerodynamic projectile design that allows very flat shooting with low recoil.
Wouldn't it be nice to explode drones with 1 bullet, don't even give them a chance to adapt.
Make sure the bullet is nice and fast (Mach 3+ muzzle velocity).
There wouldn't be enough time for the borg to process and stop the bullet.
It also makes for a simple dumb explosive rocket for StarFleet Ground Troops to carry around in a pistol / rifle format.