I changed my Lee die expander out for one from a .303 so I can seat .311" bullets. The standard one with Lee dies is for .308" bullets.
I do not know what size bullets the Lee Classic Loader is set to size for.
I load .310/.311 jacketed, but mostly use cast bullets I made at .312-.313".
The Lee Powder measure kit (dippers) is nice, and so is the perfect powder measure, or any other roatating drum powder measure (RCBS etc). But with any of the adjustable measures you will need a scale to set it so you know how much powder it drops. With the fixed dippers a scale is nice to tell you wat you are getting exacty but they are cose enough to be safe.
If for example you use the 3.1cc to scoop Varget (should be 42.4gr) and it actually scoops 42.8gr with your lot of Varget and your specific load data allows 41 - 45.5grmax Varget your'e set. A scale of course allows you to scoop exacting amounts or set up a powder thrower to whatever you want. I find with practice you can get the dippers to be within .1gr per scoop using Lee's friends method described in the Lee manual.