That would be nice, except there is no such thing as a repeating heavy crossbow. A repeating crossbow packs the same punch as a light crossbow (d8).

Also, a repeating crossbow takes a full round action to reload the case of bolts into. I think as a GM I'd reduce that to a move equivelant action with the rapid reload feat as you would still be quicker on the draw, but it's still a complex action.

A repeating crossbow that never ran out of ammo would be pretty powerful indeed...

I think the idea itself of a repeating crossbow is pretty intriging, but as far as AD&D goes, they've glossed over a lot with the weapon already. In history such weapons were made, and there were several ways of doing it. The 'case of bolts' mounted on top idea was nice in that it sped loading time removing the drawing of the bolt from the quiver. Unfortunately, it made the weapon much harder to hold and aim... but you still had to draw the string back and snag it on the catch with each shot. You couldn't just pull the trigger like a semi-auto pistol. Then there was the 'stack a bunch of crossbows on the same stock' method. Basically, mount a bunch of bow, string and catch/trigger assemblies all together. Each bow held a bolt, and each had to be fired seperately. Packed a wallop when letting them off, but you could forget about reloading the weapon after it was empty before the battle was over. It was also extremely heavy and unweildy.

Therefore, the entire concept of the 'repeating crossbow' as presented in the AD&D system is a bit lost to me. They seem to gloss over the fact that you still have to @#%$ a string back for each bolt that is fired. Even in modern times with all the technology we have access to, I don't believe anyone has come up with an amiable solution to that (and still being able to call the weapon a crossbow).

Know what I mean?