what shot size (steel shot)

[DIVR6347]

hi all
i just got a cz 712 semi auto and the suggestion has been to put about 4 boxes of 3 inchers thru it to loosen the action
all thats availible to me in 3 inch is steel shot  i have never shot steel shot before  so my question would be what size 3 in steel loads would work good for breaking in the action  i have no idea on the shot sizes for steel
so any help would be great
thanks guys
divr6347    

[PA-Joe]

You can use 7 for trap 6 for small game 3&1 for geese T for coyote. Check you state code for max size.