This what I came up with from the ipsc.invision.com a forum for international competition shooters It looks to me after I received this info flying through Hong Kong is very doable.
This is from Vince Pinto one of the Moderators on that forum
The primary issue is that Hong Kong Airport lacks a facility on the tarmac for the temporary storage of arms and ammunition. If it's only a 1-2 hour transit, they'll just send a warm body to guard them, but they'll grab you from the transit lounge and ask you to identify your bags. This is because they know the guns are there but, despite the tags, they want physical confirmation they are guarding the correct bags, not a suitcase full of Hello Kitty dolls.
If the transit time is longer, as is the case with you, the guns must be taken to Customs inside the terminal for storage in their armoury. This is when it becomes a pain in the neck, because they require the owner to be present and to sign the forms.
Customs (and Police) are cool guys, and they're just doing their job, but the process is labourious. It's the Airport Ninjas Security guys (they weigh 90lbs wringing wet, but they carry a large black toothpick night stick!), who usually behave like they found a nuclear device. Be afraid. Not!
Anyway, the document below, which I prepared in respect of the World Shoot in Bali, should answer your questions.
Attached File hongkong.pdf 129.81KB 7 downloads
File may not download I'm not sure how to attach it