The Obama administration has most gun owners on edge and big purchases of ammo by federal government agencies aren’t helping. But a firearms trainer at a suburban Houston gun store says there's a legitimate reason for it.

In recent months the U.S. Postal Service made a big ammo buy that caused concern. But Chuck Persinger at Spring Guns & Ammo says they do it every year.

"They have postal inspectors and they have to qualify -- they carry a firearm so they have to qualify."

Now Homeland Security has raised some eyebrows by purchasing 141,000 rounds of sniper ammo.

"You've got Customs; a bunch of law enforcement agencies altogether and they have SWAT teams and they have to train."

Persinger says the feds have always done this, but we didn't pay much attention until the Obama administration started scaring gun buyers.

"As far as the ammo goes, the NRA came out with it and if anybody is going to come out with the truth it's gonna be NRA on it. I was surprised when I read it but it made sense."