I find a 6.03mm to be the best bore size, as with 6.01 almost anything will jam it, and that's never any fun. The downside to L96 is the barrels have a specific cut although you can get aftermarket hop-up chambers that fit AEG cut barrel (PDi makes a good one I know, have it in mine.)
If you ever need help with this rifle, pm me. I have been working on mine and it is now a trigger away from having all internal stock parts out of it.