DENVER
07/01/2013 10:09 am ET

Colorado's New Gun Control Laws Go Into Effect Today

Colorado's sweeping new gun control legislation signed into law by Gov. John Hickenlooper in March finally goes into effect today.

Universal background checks for all private gun sales and a ban on ammunition magazines that hold more than 15 rounds are among the new and controversial gun control laws that begin Monday.

The ban on high-capacity magazines law remains the most controversial with gun rights activists fighting against it and the majority of Colorado sheriffs challenging the law as unconstitutional.

Over the weekend several gun rights groups held rallies in opposition to the limit on ammunition magazines including Magpul, an Erie-based gun accessory manufacturer that was a vocal opponent of the gun control legislation, which gave away 1,500 30-round ammo magazines for free at the "Farewell to Arms Freedom Festival" at Infinity Park in Glendale on Saturday.

Magpul vowed to leave the state after the gun-control legislation was signed into law and in April, for the first time in its history, began to manufacture its firearm accessories outside of Colorado.

Earlier in June, Magpul put the "Free Colorado" and "Boulder Airlift" limited-run high-capacity magazines for sale as part of an effort to raise money to fight gun control efforts here in Colorado and across the nation. The company announced that it sold out of the special run magazine in just hours.

In Weld County on Saturday, a group of Colorado gun owners gathered for the Colorado Freedom Shoot which was dubbed the final opportunity to shoot high-capacity magazines in the state before the ban took effect, The Greeley Tribune reported.

"There's already laws against killing people," Ray Sanchez, an attendee of the Colorado Freedom Shoot, said to The Greeley Tribune. "There's already laws against shooting people. But people go and do it anyway," Sanchez said. "So if someone is willing to go and do something like that, what's it take to bring in a magazine from another state that is more than 15 rounds, or whatever arbitrary number they picked?"

7News reports that a group of gun rights activists are planning new events to defy the state law, one is scheduled to take place on Monday at the Capitol and urges gun owners to buy, sell and swap magazines that hold more than 15 rounds.

Nearly all of Colorado's county sheriffs have signed onto a federal lawsuit against the state of Colorado arguing that the new gun laws pushed by Democrats and signed by Gov. Hickenlooper violate the Second and Fourteenth Amendments.

Sheriffs in 54 of Colorado's 64 counties joined the lawsuit with only Grand, Eagle, Pueblo, Chaffee, Conejos, San Miguel, Boulder, Pitkin, Broomfield and Denver counties opting-out.

The lawsuit takes aim at both universal background checks and the ban on high-capacity magazines. The sheriffs' next date in court in July 10, but the group is hoping to temporarily block the ammo magazine limit while the lawsuit takes place.

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