What sort of spells would work on hand cannons or how could you enchant same?
I think they had those back in the middle ages,right?
Well, they were introduced during the middle ages at least. And early ones are extremely crude, rare and troublesome(for the user).
If i were to enchant one, i would make it lighter, put in a CrIg spell as "ignition"(removing the need for a firing hole and the need to carry a constantly burning match, greatly improving handling, range and reliability), and two(one??) CrTe spell with Diameter duration that loads it (allowing a perfect and identical ball and charge every time, much improving average accuracy and range as well as providing infinite ammo), and then a ReTe spell absorb recoil.
In resources used, its extremely ineffective compared to just making a small wand that fires off metal bullets on command.
But it could possibly be used as a way to reduce how obvious it is that magic is involved.
If you're going to the trouble of having a tube and a CrIg propulsion, I would use a non-magically-created bullet so that it is not magically resisted. Re Te can be used to load fast. Perhaps recoil could be ignored using the "medieval paradigm" excuse?
On the other hand, to be minimalist, if you think that manual loading and igniting is a cool element, perhaps magic use can be reduced to ReTe strengthening of the tube to reduce explosive botches...
any magical ammo for the magical hand cannon?
maybe like spring armor that wraps enemies in GIANT springs.
Any magical ammo needs to penetrate and thus is pointless against mages.
And pretty much anything will kill a mundane.
not if it's entention is to trap & NOT kill the person being shot at.
Intention, not entention (spelling is important. If you can't spell, get Google Chrome, it comes with a built in spellchecker for stuff on the net
(Off topic, but spelling and capitalisation matter))
We all make typos. It is a feature of the modern world and the electronic age. I work as a librarian and consider myself to be a professional pedant, but I too make typos in my enthusiasm to post.
Getting back to the point in question though.
ReTe in the forging process, or better still a Verditiius mage constructing can create a flawless barrel that would never break (at least not burst due to imperfect casting & seams (the most common reason).
As already pointed out magical bullets for harm are a bit pointless on account of them beign resisted by parma and bullets pass through armour - thats the reason they because so popular.
Magic 'ammo' of other types is an interesting option though - such as for entrapment, noxious gas dispensation etc.
This brings up an interesting possibility. Black powder weapons and other middle ages oddities might provide just the vehicle to use Hermetic magic in the interference of mundane politics... discreetly... Such devices could be crafted as they APPEAR to be mundane weapons devised with eastern wisdom for example, but are in fact simply enchanted devices with cosmetics that mimic these effects. Byzantine ships with Greek fire are such a legend that would lend itself perfectly well to being, in fact, a magical device attached to the prow of a ship. Battering rams can be swung apparently by muscle power but in fact hit with much greater force... All very interesting options I had not previously considered.
I know, but still, spelling is important. And I did offer a way to compensate for typos.
(And yes, I had to use that spell checker myself from time to time)
And while that's possible, you still leave a sigil, so you'd better avoid attracting the attention of a quaisitor still.
That armour is useless against firearms is a myth.
A VERY good show of that is the 2 battles in 17th century when Polish heavy cavalry smashed up Swedish musketeers. One of the main reasons for being so successful at these times were that too many bullets from the musketeers failed to penetrate the heavy armour of the cavalry.
The reason firearms became popular was that while it took 10 years to get a good archer, it took half a year to train a good musketeer.
A bullet is MORE likely to penetrate armour, but put a well trained company of archers vs one of musketeers, and the archers will win without question.
shudder "Its a feature not a bug"...(classic statement about computer software, usually the latest Windows version) 
I most certainly hope not. And while typos is one thing, we ALL DO make them, it is a major problem how the average quality of text as well as translations have dropped so drastically over the last few decades. And it got alot WORSE once spellcheckers became common. People rely far too much on them and make stupid mistakes, or even let themselves be overruled when they´re right and the software is wrong, which is just all too common.
(among other things i have worked as a translator and proofreader so maybe you can understand why im not happy about it)
Exactly. While i cant see much of any other good reasons for such items, interfering "covertly" in mundane matters could make it worth the effort for someone involved enough.
Never use the horrid things myself, spellcheckers are pure eeeeevil.
People need to learn the language themselves first of all, no spellchecker can make up for that.
well excuuuuuuuuuse me!
any more thoughts on magicaL hand cannons?