As Tool says, jsb
One of my ev2 barrels likes Exacts sized down to 4.50, the other can shoot straight from tin.
With express both liked sized rather than from tin (odd flyer), but one was still 4.50 the other 4.52.
Exacts are easier to shoot than express and thats why most use them.
The new batches of Exacts with the new design red label (probably all you will find on sale now) are fine for weight, there is no neeed to weigh them. I have done a few tins from different batches and they all came in 8.3 - 8.5 = same landing point at 55 yards.
Lube seems to do nothing to accuaracy but does keep the barrel clean and thats essential in jy ev2 and all others i have seen. As Holly once said about the ev2, Chocolate barrel!