Just remember, your weights will not be my weights and visa verse. Humidity, brand and batch all effect the weight of your powder.
Regardless of the actual weight of your charge, consistancy is the key. Personally I don't weigh my CB charges other than with a spout and it's pretty consistant, but I'm not shooting competively, I'm just havin' fun. I do weigh all my BP cartridge charges, mainly because they can sit on the scale while I put the wad in the last case charged and put it in the rack.
If you really want to see how consistant your charges are, find somebody with a chronograph. You may find that your spout is almost as consistant as a scale.
By the way, I'm not a rifle shooter, but 100gr by weight of 777 sounds a little stiff doesn't it?