You are probably thinking of the .50 caliber Barrett, first made in 1982 by Barrett Firearms Manufacturing.
the 50 cal has 10 and the intervention has 5
5.8 feet
No. The .50 AE is 33mm in length. The .50 Browning Machine Gun rounds, as used in the Barrett, are 99mm in length. Very substantial difference.
see the link below
Internet, MidWay USA, Barrett
No Some are. Which model Barret?
Just under 8000 feet.
acog definitely
About 14 kilogramms. It is 1.14m long.
180 dB is a result from the barrett M107A1 50 cal long rifle.
Barrett makes a range of .50 rifles. Assuming you're referring to the M82 (M107 in military nomenclature), it was designed in 1980.