Gun dealers and buyers are right to question the cost and scope of the new instant background check system coming later this year. The feigned surprise of pro-gun groups that it’s coming at all is a bit hard to take.

As of Dec. 1, anyone who buys any type of gun from a licensed dealer must first pass an on-the-spot background check, an instant computer search of criminal and mental health records, military discharge rosters and other databases that, it is hoped, will weed out convicted felons and others prohibited by law from possessing firearms. This new system will replace the current five-day waiting period for handgun purchases, a delay which many understandably find offensive, and also will scrutinize buyers of long guns — rifles and shotguns.

Critics of the new system have a couple of legitimate concerns. First, the proposed cost, an estimated $13 to $16 per background check, does seem an awfully high price to scan databases that already exist. In this age of the user fee, it is reasonable that those on either the buying or selling end of the gun trade should pay the freight, but the fee should be just enough to cover expenses and not be used to fund the Bureau of Alcohol, Tobacco and Firearms. If it costs more than a couple of bucks to run a name and Social Security number through a computer, someone has a lot of explaining to do.

Second, once a reasonable, actual-cost fee is set, there must be a solid guarantee that it will stay that way. One need not be a card-carrying member of the black helicopter crowd to worry that a fee not firmly anchored to actual cost of service could escalate to a level that becomes de facto gun control.

And third, the public must be assured that a background check to make it more difficult for convicted criminals to buy guns does not become a backdoor to national gun registration. If Congress wants national gun registration, let it muster the courage to try to enact a law to that effect. It should not be done by Treasury Department administrative fiat.

Legitimate as those concerns are, it is highly annoying to hear groups such as the National Rifle Association and the Gun Owners of America sputtering about what a surprise this is and how peeved millions of law-abiding, Second Amendment-cherishing Americans will be come Dec. 1. This provision was written into the 1993 Brady Bill. These organizations followed the crafting of that legislation closely and, in fact, pushed hard for the switch from the waiting period to the less onerous instant check. They are not strangers to publicity, they are not at all shy about lobbying Congress or about communicating with their memberships on vital issues. Pro-gun groups knew five years ago this switch was coming and that long guns would be included. They cannot now suggest the government is pulling a fast one and they certainly have no business riling up the public needlessly.

The government has a responsibility to keep this instant check program within the strict confines of what it was intended to do, at a cost to the public that is its true cost. The gun lobby, likewise, has a responsibility to keep it real.