So it would probably work somewhat like this: compress M mass units of matter into a black hole, attach it to a container and then fling it at the enemy and have the container stop working at the appropriate time.
Wait, why do we need a container?
The operation of the antimatter equivalent could be simplified as the following: Load a standard coilgun shell at the ship's normal cannon. Attach an antimatter converter automanipulator on it. Fire the slug and then convert it to antimatter as soon as it exits the barrel of the coilgun (or if it's cheaper, have the coilgun be a vacuum and convert it before firing it, since it will presumably retain the same physical properties).
It would be cheaper, because we wouldn't be firing automanips with each shot.
Assuming that you
can turn matter into antimatter with automanips; nothing like this has been done with ANY space magic, ever. Moving things around? That's easy. We've never seen anyone turn it into antimatter, though.
So in the first case, assuming the black hole converts its entire mass to energy, we have M mass units equivalent amount of energy released somewhere near or on the enemy ship...
Not all energy is energy we want, you know.
...and it is likely that not all of the antimatter will react with matter, bringing the amount of energy released somewhere below but still close to 2M mass unit equivalent amount of energy.
Not particularly close, since after the first "layer" or so of antimatter the rest would be blown away from the ship from the force of the explosion.
That is, assuming the act of converting a shell into antimatter and compressing a shell into a black hole require a roughly equally priced automanipulator.
Price could become a factor once you start weighing in that you could create antimatter conventionally, without the use of automanipulators, so then it would become a question of whether or not it is preferable (read cheaper and easier) to create automanipulators or antimatter and whether or not the risk of storing antimatter is greater than the risk of storing automanipulators.
First off, remember that we don't have any clue if automanips
can turn matter into antimatter. There's been nothing to suggest it's possible.
Second off, well...creating antimatter in ANY quantity requires a lot of energy for a little bit of antimatter. Separating it from the corresponding matter before they annihilate each other is a non-trivial task, as is storing it. Then you need to transport it...and then you have limited ammunition.
Don't forget, automanips can be as dangerous as antimatter. Who's to say that a stray shot hitting your automanipulator storage won't cause an overload that would cause your entire ship or even nearby ships to collapse into a temporary black hole or have your entire fleet ripped apart by gravity distortions?
Automanips can destroy the single ship, but it's not likely that they'd affect anything else. Remember, space is big, really big. Even the biggest space magic problems we've had haven't extended more than a couple hundred meters or so from the originator, and with the kind of ship that we'd be using this on, that might not even cover the entire ship. Yeah, it gets bigger with bigger manips, but if the ships are flying in halfway-intelligent formations, they'd be far enough that the only effect they'd experience would be "pretty lights". And remember, when piecewise was questioned on matters relating to formation distance, his reply was less "well, things aren't like that" and more "things are like that, but we're ignoring that in favor of what the dice say". So neither's going to destroy more than the singular ship.
As to which is more likely to malfunction...well...you need to hit an automanip directly to damage it, but antimatter containment can fail fairly easily (in comparison). There's a lot of important parts to even the simplest. PRetty much the best idea we've got at present is an electromagnetic containment unit, which would need to be holding (say) anti-H
+. But if the particles weren't 100% protons or 100% electrons, there would probably be some that lost or gained enough electrons to no longer be charged...and you only need one atom to drift into the protective equipment to detonate strongly enough to screw it up, which leads to containment issues.
Both are stupidly dangerous and should be used with caution, if at all.
Ships already have automanips for their weapon systems, so no they wouldn't be more dangerous for relying on automanips.
Also, the shell is not a solid unbreakable sphere. Yes, some of the energy will cause some of the antimatter to stop or be repelled but the shell is fired at insane seeds and will crumple and shatter on impact, ensuring more of it hits the target.
And only a fraction of any bit would hit the ship.
Incidentally, this means that "buckshot" would make the overall thing worse.