Police in India's northern Uttar Pradesh state on Sunday bid goodbye to the historic British-era bolt-action rifles after using them for one last salute during the annual Republic Day parade.

The Lee-Enfield .303 rifle was the main firearm of British colonial military forces and, despite being designated "obsolete" around 25 years ago, it has been the main weapon used by police in the northern Indian state for over seven decades after being introduced in 1945.

The rifle – used by the British during the two World Wars – fires one shot at a time, after which the barrel needs to be reloaded by pulling the bolt.

"They have been in use since independence [from the British in 1947] and now they'll be replaced by INSAS (Indian Small Arms System) and SLRs (Self-Loading Rifles)," said police superintendent Amit Verma.

As many as 45,000 of the rifles were being used by the state police, Verma said, and the model was a favorite among constables due to accuracy and sturdiness.

"If there was an award for guns on the basis of their performance, .303s or bolt action rifles would have certainly bagged one," former director general of police Brij Lal told the Hindustan Times newspaper.

"This [.303) rifle is a fantastic weapon and has served us brilliantly in various operations in the past," police additional director general Bijaya Kumar Maurya told AFP. 

"But it being a bolt action weapon with low magazine capacity, it was time for a change. Its production has also discontinued so there was all the more need for an upgrade," he added.

Maurya said the new automatic rifles would "add to the confidence of our officers" and would result in improved policing. "The criminals will naturally face the heat when they'll face officers armed with automatic weapons."

The rifles will be returned to a gun factory in Ishapore in West Bengal state where they will be converted into anti-riot guns, spokesman Saurabh Singh told AFP.

Saroj Kumar Mishra, a constable with the Uttar Pradesh police since 1982, said he would miss the heavy-duty rifle. "The weapon is as smooth as butter even after 20 rounds of back-to-back firing," he was quoted as saying by the Hindustan Times.

"This feature is perhaps the most important one which we often miss in the modern day weapons."