Rambler said copper production amounted to 521 tonnes in October, up from 328t in September and more than double the figure of 197t reported for June.
Rambler closed a US$22 million debt financing package at the end of October. CEO Toby Bradbury said Monday's operational update "shows that, even before closing the financing, we have been steadily improving our operations".
"The mine produced these improved results whilst remaining in development mode to deliver multiple stopes by the end of 2021 which underpins our goal of sustainably achieving 1,350 tonnes per day mill feed at an average head grade of 2% copper," said Bradbury.
Rambler has been producing at Ming since 2012 but was forced to scale back operations in 2020 due to low copper prices.
Rambler shares were valued at 39.25p at market close on Monday, capitalising the company at £52.4 million.