Arrested and charged with possession with intent to deliver cocaine was 42-year-old Steven C. Underwood, Jones said.
Underwood was arraigned before Berkeley County Magistrate Harold "Gene" Darlington and released on $15,000 bond, police said.
Five deputies executed a search warrant at the home late Saturday night and found 84 grams of suspected cocaine, which had a street value of $5,000, 16 grams of suspected marijuana, nine grams of a suspected pain killer known as Demerol, two sets of electronic scales, two sets of portable scales and other items, police said.
The Chinese assault rifles were among 22 long-barrelled guns taken from the home, deputies said. A deputy investigating the case said the assault rifles were fairly easy to purchase in the county before the federal government cracked down on the weapons.
Five handguns also were found in the trailer, police said.
Jones said deputies were tipped off about the operation after an informant gave authorities information about the case about a month ago. The home was located just outside Gerrardstown along Virginia Line Road, but Jones would not say exactly where it was situated.
Jones said there is still a considerable amount of crack and marijuana trafficking in Berkeley County, and he said he made it clear in his recent campaign for sheriff that he would make drug interdiction a priority.
"This is just one in the county," Jones said, referring to Saturday's arrest. "That's what you have to work with. One at a time," he said.