INDIANAPOLIS ― The Department of Homeland Security plans to get rid of all its 7.62mm NATO, or .308 caliber, long-range rifle ammunition and replace it with an intermediate caliber that Special Operations snipers will field next year — the 6.5mm Creedmoor.

Speaking Monday during a panel at the National Defense Industrial Association Armament Systems Forum here, Devin Patterson, a DHS engineer, told the audience that the switch would give their “tactical observers,” civilian speak for snipers, a more accurate round for their sensitive security missions.

And because the dimensions of the cartridge are not drastically different, the change mostly involves just a barrel change.

“It’s an easy swap,” Patterson said.

“Law enforcement ruled out .260 Remington right off the bat,” Patterson said.

That’s because with the 6.5mm, they can continue to use the same NATO-spec magazines that are in use with the 7.62mm.

While Special Operations Command snipers have also adopted the same caliber, cartridge configurations could be somewhat different because of DHS mission-specific concerns.

They are evaluating a hybrid of open-tip match ammunition with improved hunting round technology.

The key, he said, is for their shooters to avoid “overpenetration.”

“Current [open-tip match] rounds don’t meet these requirements,” he said.

As both DHS and SOCOM snipers make the switch to 6.5mm, the regular Army is developing its own weapon and cartridge configuration.

That project, under the Next Generation Squad Rifle umbrella, is likely to end the military’s use of 5.56mm ammunition, a round that’s been controversial since it was first adopted by the Pentagon more than half a century ago.

Much of their testing has fallen within that range but isn’t likely to produce a prototype weapon for testing for another two years.