The 27 commemorative guns were stolen from the Lithgow Small Arms Factory Museum, in the NSW Blue Mountains region, early on August 25 by men who had their faces covered.
The weapons included one from the 1700s and a pistol gifted by the Sultan of Oman.
Detectives were told the handguns, worth more than $200,000, could be made operational with modifications.
On Friday, three men aged 27, 41 and 46 were refused bail in Nowra Local Court on charges related to the alleged robbery.
They were arrested on Thursday after raids in the towns of Vincentia, Nowra, Darbys Falls and Sanctuary Point.
Officers seized 13 of the stolen firearms, as well as a shotgun and ammunition, a luxury car, seven NSW vehicle registration plates, $3500 in cash, electronic devices, methamphetamine and cannabis.
The 41-year-old was charged with aggravated break and enter, participating in a criminal group and stealing a motor vehicle.
The other men were both charged with offences including aggravated break and enter.
Three men have been charged over the theft of 27 handguns from a regional NSW museum. (HANDOUT/NSW POLICE)
Drug and Firearms Squad commander John Watson said police would allege that the "syndicate" had stolen the firearms for the "sole purpose to make profit from the sale of these guns".
Police will also allege that the men were attempting to manufacture firing pins for the firearms.
Fourteen guns stolen from the museum remain missing and may have been sold to "unwitting" members of the public, Detective Superintendent Watson said.
"Due to this, we are asking those members of the public to return these firearms as quickly as they can," he said.
People would not face prosecution if they turned in the weapons to a registered firearms dealer or police station, Det Supt Watson said.
The partial resolution of the matter was "bittersweet" for those at the community-run museum, he added.
"There's a feeling of appreciation but, more importantly, (they're) very keen to get their hands back on their exhibits and artefacts."
The volunteer-run museum opened in 1998 on the site of a former small-arms factory, which was established in 1912.
14°C