WINCHESTER SUPER X 12G BB 36GAmunition is click and collect only, a current Firearms Licence will be needed to complete collection. Shot size BB 1315 fps 36 grain Field shotshells are used for hunting, while target shotshells are used to break clays. Field loads are generally considered to cover shot sizes 6 all the way up to size T and include all of the buckshot sizes. Target shotshells generally start at shot size 7, and end at shot size 9. Of course, there are exceptions.