Quote Originally Posted by Incanur View Post
Crossbows are so confusing.

Based on the historical record, you'd think the larger, heavier crossbow were more powerful than any bow, but so far replicas don't support this.

Tod Todeschini just came out with a video testing a 1,250lb windlass crossbow. He did a distance test and only managed 235 yards with a 3.1oz bolt.

Ralph Payne-Gallwey claimed to have shot a 3oz bolt 460 yards with a 1,200lb 15th/16th-century crossbow. (He replaced the parts that had decayed, but at least the steel prod was original.)

This is a huge gap in performance. It depends on aerodynamics, but based on the tests in The Great Warbow, the Payne-Gallwey shot indicates 220+ J of initial kinetic energy. You'd need a ridiculous heavy (220+lb?) yew bow to shoot a 3oz project so fast, if it could be done at all.

By contrast, Tod's distance record indicates an initial kinetic energy under 120 J. (It's possible the bolts he used are just really bad for distance shooting, and/or the bolts Payne-Gallwey used were really good.)

According to current tests and models, a mere 80lb Manchu bow could deliver 120+ J with a heavy arrow (3-4 ounces, as Manchu archers frequently used).

I don't really know what's going on.
With all due respect to Leo, who is a treasure to the community, he's not making weapons for war or hunting, he's making weapons for re-enactors and living history people. A 1,200 lb draw crossbow is a potentially very dangerous artifact. Certain aspects of the prod and the string in particular can't be pushed as far as they would when these things were used for war (or hunting bears, say)

And for all his expertise, Leo is one guy, one of a relative handful trying to revive traditions from 500 years ago which are no longer fully understood. I think it will take some time before we have the mystery of the medieval crossbow (which works in a completely different way than modern ones) 'cracked', so to speak.

G