An Iowa anti-gun group is praising a move by the nation’s largest retailer to toughen its policy on gun sales. Federal law requires retailers to wait three-days for a background check when selling a gun. But John Johnson, the executive director of Iowans for the Prevention of Gun Violence, says there’s a loophole that WalMart has agreed to close.If the check isn’t complete in the three days — retailers can sell the gun and then cops have to try and get it back if something turns up later. Johnson says WalMart decided their stores won’t let customers take the guns until the check is final. Johnson says under current law, some criminals could get a gun.He says if it’s later proven that someone shouldn’t have a gun, then it’s up to police to go and recover the weapon. Johnson praises WalMart for taking action without being forced to.He says it’s also an example of a private business voluntarily taking action without the need for additional federal regulations. Johnson says K-Mart officials have told him they also require customers to wait until the final check is completed before handing over the guns, as does the Scheel’s sporting goods chain. He says K’s Merchandise has a corporate policy of releasing the gun after the three-day limit.