He soon realised that she was serious and was concerned because she was so far from home, he said.
X-rays and CT scans from Cairns Hospital showed his wife had no neurological or nerve damage to her leg.
"The bullet hasn't fragmented, that would have been one of the problems. But I've told her to bring it (the bullet) home with her, he said.
The incident has not dampened the family's willingness to do further volunteer work overseas. Mr Franzoi said he and younger son, 13-year-old Ben, would hopefully do the same trip next year.
Papua New Guinea at a glance
Papua New Guinea occupies the eastern part of the world's second largest island and is prey to volcanic activity, earthquakes and tidal waves. It has more than 700 native tongues. About 80 per cent of its people live in rural areas with few facilities.
Politics: Separatist rebellion on Bougainville was resolved in 2005.
Economy: With abundant oil and gas, Papua New Guinea has potential to become a major energy exporter.
International: Australia has been a major supplier of aid and peace-keeping forces.