You need to give us more information. Which model of rifle do you have that's chambered for the 6.5x55??
You're asking for answers that could be dangerous to you and those close by.
For the old Swede milsurps,
120 grain load, which is close enough:
CCI 200 primer / 123 grain bullet / start with 33.5 grains of IMR3031 and work up to 38.0 grains.
From personal experience, BLC2 isn't really bulky enough to get a good fill ratio in the case and you should use magnum primers with Ball powders for consistent ignition 38.0 grains will get you started. There's a good reason manuals don't list this powder for this cartridge.
For the 140 grain loads,
Start at 31 grains of IMR3031 and work up to 35.0
IMR3031 is IMHO, to fast for the 6.5 diameter bores, with cartridges that have generous powder capacities.
I know CGN is convenient, but why aren't you going onto other sites, dedicated to reloading?? Most manufacturers will explain why some powders are borderline or unsuitable for certain cartridge/bullet combos.