Steyr Mannlicher Business Group would probably be your best bet for sending a resume into. Steyr Arms Inc. of Cumming, GA is for sales information and what not, but they might be the best place to contact for starters. However, I would imagine that the Steyr Mannlicher GmbH & Co.KG would be the place that is concerned with reviewing job applicants as they are the International Headquaters in Austria.
REVIEW THIS WEBSITE
The above site describes their business structure and has contact information for the various branches of the company. I also think it would be a good idea to read up on as much Steyr Mannlicher information as possible to use in a nice cover letter to show them you know the company. Keep us informed on what you find out as I think it would really be something to work for one of the oldest firearms companies on the cutting edge of the industry. Be prepared to travel to Austria and perhaps even Malaysia though if you were employed.