Sorry if this has been discussed before, but all i can find is bits of information from previous threads.
I am due to fly from the UK to the US for a longish stay of approx 3 months and am aware of the 32kg (70lb) limits on hold baggage which i aim to be within.
I also wish to take a quantity of rather expensive photographic equipment with me (i am a little more than just an everyday 'snapper') which i aim to take as hand baggage, which i understand has a weight restriction of 7kg (?).
In the unlikely event that i am asked to check the bag containing the photographic equipment due to size or weight, i am reluctant to check not only valuable but also fragile items mainly due to the stories within these forum's of lost or damaged valuables from checked luggage.
If i was to cargo these items to the US i would obviously have to declare a value for insurance purposes which may attract the attention of US customs.

My question is...
Will i be charged import duty by customs on valuable items that are for my own personal use?
Has anyone here have experience of a similar situation?

I have very limited experience with cargo (sent an oven home from New Zealand and a container of stuff from Bali), but I'll share my experiences.

You may want to send through a regular cargo company (UPS, FedEx) as when I shipped the oven cargo through my airline I was told they didn't offer insurance. I'd check on this in advance.

As for determining duty, there's a website where you can try to figure it out yourself (link below), but it's easiest to just call a customs office or send them an email from the link (the duty book is 3000+ pages). It's very confusing to try to figure it out on your own. I've not paid any duty on the things I brought in for my own use (kitchen full of appliances and a lot of furniture), but when I was at the customs office for one of my shipments another family was having to pay duty on their used kitchen items because customs decided they had a sufficient quantity that they would be using it commercially.

http://www.cbp.gov/xp/cgov/import/du...etermining.xml

It's quite likely your baggage allowance is actually much larger than you think. You should be allowed two pieces of 32 kg/70 lbs. baggage on an international flight, not just one. I believe this is an IATA rule, standard across all airlines on international routes. The quantity of carry-on luggage allowed is more variable. US-based carriers will generally let you take your kitchen sink: one "carry-on bag" (up to 18 kg/40 lbs. on AA) and one "personal item" (not well defined, but basically no larger than a briefcase/purse/small backpack).

When my Canadian girlfriend returned home I fedexed her stuff and declared it as personal items, any frieght company would help you out with the documentation.

Another option is an ATA Garnet/Carnet, you'll pay a processing fee and deposit as security which will be refunded on re-export of the items. Bear in mind I've only ever used those for business items so it might not be suitable. Give Customs and Excise a call and they'll let you know if it's possible.