not strictly a bow, but...

[stuckinthemud]

OK, this is a question about horn and sinew construction, so I'll risk it, but if a moderator wants to remove the post I won't be hurt......
I am going to build a composite cross-bow prod looking to get as close to German 15th century construction as I realistically can but I do not know the quantities of horn I need for a light cross-bow of say 200lb, or even the type of horn - water-buffalo, I suppose .  I am also not certain as to whether to use a yew core, but can't get any definitive answers, so any and all help/advice would be very welcome.

[mikekeswick]

Don't use yew unless you are going to use an epoxy to glue horn to it.
A core of some sort would be adviseable as it will aid stability a lot.
Personally i'd use hard maple (acer saccharum).
Water buffalo is the best horn.
aim for an even thickness of horn, wood and sinew.
Dimensions depend on the length of prod and length of intended draw.