tm bretta problems

[bushman]

hey everyone. So i just got a tm Beretta from one of my friends, and now i have a few questions? first is a few of the mags are kinda funky! you fill them up all the way and then you stick them into the gun, that is fine but when you shoot it, it does not have enough power to advance the next time. so i have to rack the slide after every shot. after a while the gas is able to advance the next bb, is it just a matter of breaking in the mags????? or is it maybe the hammer spring for the valve? also the person i got it from said that it had high flo valves built into the gun??????? could that b the problem? thanks for the help

[bushman]

it is the beginning of the mags it can get off like 35 shots with the good mags, or by racking the slide every time lol