Five years after making its debut in the Israel Defense Force’s standing combat units, the Israeli-developed Tavor assault rifle is set to be introduced into the army’s reserve units, where it would replace the older American-made M-16, Maariv reported on Thursday.

Starting in 2006, a number of the army’s infantry brigades swapped their M-16s for the new Tavor. Some six years later, thousands of soldiers have finished their mandatory service never having handled an M-16.

Reserve soldiers called up during Operation Pillar of Defense in Gaza last month were handed M-16 rifles, which have been in the IDF’s service for the past two decades. After the operation in Gaza ended, decision-makers decided to expedite the adoption of the weapon across the IDF.

For the veteran reserve soldiers, who had handled the M-16 in combat situations such as the Second Lebanon War, Operation Cast Lead and even in the security strip in Lebanon before Israel’s withdrawal in 2000, it would be a huge change.

“It’s a serious challenge,” Maj. Roniel Turgeman told Maariv. Taking someone who knows how to operate one weapon and teaching them to use a new one in a short time period and with a limited number of training days wasn’t a simple project, the officer — in charge of weaponry for Infantry and Paratroopers — said, noting that the transition would take a few years.