Police have launched an investigation into the theft which included dozens of handguns and assault rifles from the PRK Arms, which is located in near Fresno Yosemite International Airport.
The break-in happened just before the weekend and the store owner told police his security cameras were not working at the time of the burglary.
Local reports said the police believe the heist took less than two minutes and the thieves broke into the store by cutting through the lock on the security bars on the door.
The news comes as the US is still coming to terms with Las Vegas shooting that left 59 people dead and 546 others injured.
The gunman, later identified as Stephen Paddock, 64, from Mesquite, Nevada, opened fire on concert-goers enjoying Route 91 Harvest Festival from his hotel window in the Mandalay Bay hotel and casino.
Intelligence agents are still struggling to comprehend the motive behind the most deadly shooting in US history.
A total of 47 firearms were recovered from three locations including Paddock’s hotel suite, his home in Mesquite, and another property associated with him in Reno, Nevada.
Bodycam footage leaked online from inside Paddock’s hotel room revealed the chilling scene police were confronted with when they stormed his bolthole.
They found a lair packed with 23 guns and ammunition, including weapons in the bath, on tripods pointing out of the smashed windows, and by Paddock’s dead body.
Photos also leaked from the crime scene show just beyond the shattered room’s entrance, an assault rifle resting on a bipod, which he used as a sniper’s perch.
Two more semi-automatic AR-15-style weapons are also pictured on the carpet, strewn with spent ammunition.
Las Vegas police have authenticated the photos and confirmed that at least 20 guns were found in the suite, including assault rifles and a handgun.
Twelve of the guns found in the hotel room were fitted with so-called bump-stock devices that allow the guns to be fired virtually as an automatic weapon.
Another graphic image – which the Express.co.uk has chosen not the publish – reveals the close-up of the killer’s face.
Police said Paddock blasted the concert crowd with bullets for nine to 11 minutes before taking his own life.
He had set up cameras inside and outside his hotel suite, which law enforcement officials believe were used to monitor the police.