Antlers:
The rules for Big Game Rifle competition in Australia are here on the forums. Try this link:

http://forums.nitroexpress.com/showflat.php?Cat=0&Number=16543

Eight of the 10 shots are against the clock. The rules are as follows:

Double Rifle
Any centerfire double rifle of minimum calibre .228.

Course of fire (National Events): 10 shots

Range......Number of Shots....Position....Timing

50 yds.............2..............Off-hand....Up to 5 minutes

50 yds.............4..............Off-hand....In 16 seconds

25 yds.............4..............Off-hand....In 16 seconds