Almost 200,000 rounds of ammunition, including 500 sniper rounds, were used in military operations to crack down on red-shirt protesters in April and May 2010, according to an army source.
The number is higher than that reported by the Truth for Reconciliation Commission (TRC) which states that only 117,923 rounds were used.
At least 92 people died in violent clashes between troops and red-shirt protesters.
According to the TRC's report, 597,500 bullets were drawn and 479,577 were returned. The TRC's report also contained a chart showing the types of ammunition used.
About 59% were shotgun shells, 30% 5.56x45mm ammunition, 8% .308 bullets, 2% blanks and the remaining 1% 7.62x51mm sniper bullets.
Following the TRC's release of its final report on the 2010 political unrest on Monday, the army rechecked the amount of ammunition used during the operations and found the number to be higher than that reported by the TRC.
According to the source, army commander Prayuth Chan-ocha ordered all units which drew the ammunition to return that which was unused for a recheck following a discrepancy.
The army's report indicates that a total of 778,750 rounds of ammunition were handed out for use in the operations. A total of 586,801 rounds were returned, which meant 191,949 were expended.
There were nine types of ammunition distributed for use including that used by snipers.
A total of 354,000 shotgun shells were drawn and 301,271 were returned, meaning 52,729 rounds were spent.
A total of 181,250 rubber shotgun bullets were drawn and 90,016 rounds were returned.
One type of bullet was not used at all. All 8,500 rounds of 5.56x45mm AP4 ammunition were returned.
A total of 17,260 rounds of 5.56x45mm M193 bullets were returned, out of 20,000 rounds.
About 150,000 5.56x45mm M855 bullets were drawn and 116,716 were returned, while 5,000 rounds from other types of ammunition were drawn and used.