The breach came to light on August 31 when soldiers from the 20 Battalion checked the Kote and Magazine and found the locks broken.
Investigators say the cache included four AK‑203 rifles, an INSAS rifle, six 9‑mm pistols, a civil pistol, three binoculars and 1,892 rounds of ammunition.
Police arrested Upputholla Mallesh alias Raju and recovered the stolen gear at his father’s house in Sainagar Colony, Achampet, Nagarkurnool district.
Mallesh allegedly plotted the heist with his cousin Mallikarjun and friend Niranjan, citing financial hardship, and enlisted ex‑regiment members Sheshulu, Vinod Kumar and Praveen to break into the armoury.
Malkajgiri Commissioner B. Sumathi said the accused had no terrorist links and that the case is being filed under the Arms Act; the suspects are scheduled for remand hearing on October 5.