Interesting, but I don't think the bolt-action system would readily apply to a crossbow. I've seen working lever-action crossbows in various configurations, but I don't think a bolt or pump action system could be successfully implemented.

I do not know that much really about projectile type weaponry. ^^; So I am not too familiar with terms and may have used them somewhat incorrectly. I wonder where the idea of a "repeating crossbow" came from within my mind? >.<

Hmm, maybe somewhat like this, but instead more mechanical, so that say, everytime the trigger is pressed, it also does the aspect of repulling the crossbow string? Instead of say, having to do it manuallly?
http://en.wikipedia.org/wiki/Repeating_crossbow

Maybe somehow the aspect of that, mechanism that normally on those, would be manually cocked with the whole push forward, pull back motion, would be automated?

Maybe by something internal, that when the trigger is pulled, it fires the bolt and then recocks it automatically?

Maybe firing one shot every 0.75-1 second? A say bow firing one shot maybe every 2 or 3 seconds?

I guess when I thought bolt action, was where like with some sniper rifles, you fire the bullet, pull the whatever it is back, it causes the shell to fly out, you put a new bullet in and then push the thing forward and fire again, verses a form of clip ssytem in modern ones.

I am unsure how to describe it. >.<

I perhaps could at least try drawing out some ideas at some point here maybe. Maybe the arrow designs as well.

Semi-automatic and fully automatic firearms operate by using either recoil or gasses released by a fired cartridge; the bullet provides the energy needed to cycle the gun's action, ejecting the spent cartridge and loading a new one into the chamber.

A revolver operates a bit differently, a piece connected to the trigger catches onto a groove on the cylinder and turns it. This rotates the cylinder and places the next chamber in line behind the barrel.

Since bolts have no power of their own, and a cylinder containing many bolts that would also be required to draw a string would likely be too cumbersome and heavy for a simple trigger mechanism (if it could be set up, you'd have to pull the trigger very hard, reducing accuracy), a crossbow that fires a bolt with every trigger pull would be quite impossible without an external power source. A complicated mechanical system powered by batteries could possibly be done, but it would be quite heavy, unreliable (lots of small parts to break or jam), and likely quite noisy...if you're going to have so much additional weight and noise, why use a crossbow at all?

Drawing back the bolt of a bolt-action rifle ejects a spent casing and loads another into the chamber. Every firearm has a bolt of some sort (with differing shape depending on action type, some are internal and not seen), a bolt-action firearm uses the bolt actively to reload, but a crossbow does not have this piece.

The classic repeating crossbow is one of the lever-action configurations I described. I've seen modern version of the weapon with a rifle-like stock, under-shelf magazine, and a lever behind the trigger like an old winchester rifle. Lever-action systems work, but pump-action systems are implausible, automatic action systems are impractical, and bolt-action systems are impossible.