The following is the rules regarding combat bows in the SCA, as taken from the rule book...
8.9 Bows
1. A combat archer may use any recurve or long bow that is in a safe and usable
condition, so long as the bow does not exceed 30 pounds (13.608kg) draw weight
at 28" (711mm) of draw.
2. The draw weight of the bow is to be determined at 28" (711mm) draw length, as
measured from the centre of the bow riser.
3. A combat archer may use a crossbow which does not exceed 600 inch pounds
(6.77 Newton meters), and is in a safe and usable condition.19 The number of
inch pounds of a crossbow is determined by multiplying the length of the power
stroke in length, eg .inches (centimeters) by the weight, eg. pounds (kilograms)
of pull at the locked position on the string. The pull weight is to be measured
at the nut, ie. string position when the crossbow is nocked. The power stroke is
the distance from the strings rest position to the locked position.
4. Compound bows and compound crossbows are not permitted.
5. Bows shall be inspected before use by a marshal, knowledgeable about archery
equipment and safety.
6. The use of hand bows and crossbows that have a period appearance is strongly
encouraged.
7. For full–contact archers, it is recommended that all bows, limbs, spars and
prods be wrapped with leather strapping to avoid accidental breakage and injury.
These rules explain themselves, and as stated, are mostly for safeties sake.
Some handy books for use in IKAC, IKCAC, Target & Combat Archery, within the SCA Australia.
Some of these are in PDF Format, and require Adobe Acrobat to read. Please use these as a guide only, and check the relevant sites for updates or rules changes as necessary.
Inter Kingdom Archery Competition Rules
Inter Kingdom Combat Archery Competition Rules
The Kingdom of Lochac Combat Handbook
The Kingdom of Lochac Combat Handbook (For
Duplex Printers)
Missile Combat Changes, Updates and Notices (July 4th, 2003) Armor Rule Change
Armour Requirements (as mentioned in the above notice).