Slitherine

But you can't pick bullets up and use them again

The repeating crossbow referred to (Chu-ko-nu) was around since fairly eary in Chinese history. It was a 10-12 round magazine fed item that shot a bolt each trigger pull. It is very difficult to find any reference to field use, as it seems to have been used mainly in field works and fortified/built-up fighting. But my favorite wishful battle is a line of these guys meeting a Roman legio - imagine a standard unit of 200 backed by the gi troops, putting out 2000 bolts just before impact (when the Romans would be getting ready to throw pilum) at a firing rate that would empty the magazine in 1 minute or less! Talk about a machine gun effect!

The actual item: http://www.atarn.org/chinese/rept_xbow.htm from an English arms manual of 1903 (yes it still was in use at that late date!)

The hand-held Chu-ko-no (as recorded during the Opium Wars) was also notoriously short-ranged, inaccurate, light-lathed and fired light bolts. Considering that it had the firing speed of regular hand bow (and required magazine reloading) it was perhaps not surprising that it was more useful as a larger fixed-position light artillery piece.

philqw78 wrote:It makes me wonder why we gave up these super weapons. IIRC Napoleonic rate of fire was 3 rounds per minute, WW2 bolt action rifle 5 rnds per minute and modern semi-automatic rifle 10 rounds per minute at deliberate rate of fire.

Yes, but at "rapid" rate it is more like 30 rounds a minute (which is what I'd be using against charging cavalry) for bolt action and semi-auto.

An ECW musketeer reenactor told me you could get a pretty good rate of fire by chucking powder and ball down the barrel and banging the butt on the ground to pack it down instead of ramming.