Picked up a tristar viper g2 semi auto 410 with the intent of letting my son and daughter shoot their first squirrels this year with it. I know ammo supply isn't the best. What's the recommended load? I assume #4,5,or 6 in 3 inch? I've only been able to find #6 3 inch. I did pick up a box of 3 inch #7.5 yesterday. Also what choke should I be using? Full?