Say I filled my air rifle to 200 bar. If I leave it alone and come back next week should it still read 200. If I leave it for a month, 3 months, 1 year should it still read 200? What is considered acceptable leakage? No leakage, 1 bar a week? I know if I filled up my car tyres to say 35psi, a month later it wouldn't be 35psi.