( CNN ) -- Colorado Gov . John Hickenlooper on Wednesday signed three gun-control measures into law , including one that will require universal background checks for gun sales . The measures also will make buyers pay for their own background checks and limit ammunition magazines to 15 rounds . The Colorado laws go into effect July 1 . What is a universal background check ? New York passed new gun-control legislation after the December killings at Newtown Elementary School , but it already had some of the stiffest gun laws in the country . Colorado , where firearms are almost as much a part of the landscape as the Rocky Mountains , is a different case . It 's long been a politically conservative state , voting Democratic just once in the 10 presidential elections that followed Lyndon Johnson 's 1964 landslide . But in recent years , its political center of gravity has tilted leftward : It went for Barack Obama in 2008 and 2012 , voted to legalize recreational marijuana last year , and state lawmakers this year voted to allow civil unions for same-sex couples . Then there 's also the bloody history of the past decade or so -- the mass shootings at Columbine High School in Littleton and a movie theater in Aurora , both Denver suburbs . Still , it took the December killings at Newtown `` to really wake up America 's conscience and realize that there were better solutions , '' said Sandy Phillips , whose daughter , Jessica Ghawi , died at Aurora . Gun-rights advocates call the Colorado bills unenforceable , feel-good measures that are likely to backfire . Nick DeCarlo owns a 2,000-acre bird-hunting preserve in Wiggins , on the prairie northeast of Denver . He says his clients are unhappy with the new legislation , particularly language that limits shotguns to eight rounds . `` They 're upset to the point where it 's like they feel Colorado is being stereotyped as a gun-control state , '' DeCarlo said . That 's going to keep businesses from moving to the state and hunters from visiting , he said . Already , he said , out-of-state customers are telling him they 've made their last visit . Richard Taylor , a manager at the Aurora gun store and range Firing Line , said the 15-round restrictions on rifle magazines are `` poorly worded '' and are likely to affect owners of nearly every magazine . He said sheriffs consider the new legislation unenforceable , and the $ 10 limit on charging individual buyers for background checks is far below the $ 50 a store typically charges for handling a transfer . Phillips said the obstacles are small compared to the potential price . `` Let 's say it takes $ 10 and 10 minutes of your time , and it 's going to protect somebody from getting a gun that they should n't have , '' she said . `` Ten dollars and 10 minutes is worth the time that it takes to save a life . '' Colorado voted to make background checks for gun-show purchases mandatory after Columbine , when investigators learned that the weapons used by the teenage killers were bought by an 18-year-old at a gun show to avoid a background check . The buyer , Robyn Anderson , later told a state House of Representatives committee that the gun purchases had been `` too easy . '' CNN 's Jennifer Feldman and Matt Smith contributed to this report .
He signs gun - control legislation in long - conservative Colorado . Gun - rights advocates call the measures unenforceable feel - good laws .