i use the LEM burger press from Bushwear
http://www.bushwear.co.uk/search.php?search=burger+press
it is not he cheapest and i cant find em for sale anywhere else BUT.....
they are totally bomb proof and very simple and quick to use. to strip & to clean.....it really will be an item you could keep for your entire stalking career then pass on!!
only thing i would recommend as others above did.....you need to use wax or cellophane circles with them so mince mixture doesnt stick....or you end up in a right faff.
not a bad thing tho coz you can stack em with wax/cellophane discs 4 high or whatever amount you want ..stick em in a freezer bag and vacuum pack them and bung em in freezer....once defrosted they arent stuck together or anything
buy the discs here
http://www.weschenfelder.co.uk/catalog/800/burger_making
buy my hog skins from them too...good site
paul