rt mag questions/efficiency

[barrel break]

hi! i am currently trading for an rt mag and need to know if a screw in 47/300 would be fine for about 500 shots (normal day for me)
thanks

[i_baked_cookies]

i have a 48/3000 and i get only 400 shots using xvalve. my fields velocity is like 250 too... mags are gas hogs. go with a 4500 tank if you have the money.