Iowa lawmakers passed the bill in May and it was signed by Reynolds on Friday.

Advocates including Republican Sen. Ken Rozenboom, an Oskaloosa farmer, said the new law is designed to help control the deer population and respond to complaints that excess deer eat corn and are hazardous to motorists.

Iowa has had January deer hunting seasons using semi-automatic rifles in the past, but they were limited to a few sparsely populated counties where deer were more of a problem. The bill is expected to expand the January hunt counties from five to as many as 15, depending on rules from the Department of Natural Resources.

The bill also will allow hunters during the new season to use smaller .223 caliber bullets, which could make it more challenging for a hunter to kill a larger animal like a deer.

Charles City Democratic Rep. Todd Prichard, a former active-duty U.S. Army soldier and now a lieutenant colonel in the U.S. Army Reserve, expressed concern when the bill was debated that the smaller caliber ammunition authorized in the bill could travel far enough to reach populated communities near hunting areas.

Deer hunting with AR-15 rifles is allowed in other states. Many states have restrictions for when they can be used and regulate the type of ammunition allowed.