How so when you only count a success on the ammo die if you roll one or more successes on the base dice?
Because that's not what ammo dice are for
The attribute and skill dice narrate your characters proficiency, the ammo dice narrate the situation.
The ammo dice are meant to simulate an increased volume of fire going downrange. If "downrange" is some hopped-up insurgent hip-firing an mg into the sunset somewhere in the general vicinity of the enemy, that increased fire is not going to do anything. Anyone with B + B or higher AGL and ranged combat will succeed 3/4 times and at least 93% when pushing rolls. Anyone under B + B should probably not be in any special forces unit anyhow. B + B also allows for up to 4 successes on the base die, regardless of how many ammo dice you use or do not. If you absolutely must not use ammo dice for some reason, just use the single shots rule.