No BB is not an actual cup size. Cup sizes vary depending on the country you are in as well as the company but usually follow the general formula of: "AA, A, B, C, D, DD/E, DDD/F, DDDD/G, H, I, J, K, L, M, N, etc.."
The reason for so many D's is because when the sizing system was developed, it did not cater for anything below an A or above a D.
Here in Australia, all sizes have a double equivalent except B and C. All the double sizes fit between their corresponding letter size and the next letter above with the exception of the AA being a smaller size than and A.
BB's are all the same size .175 for all the BB guns.
BB = ball bearing. One size that is used allot is the 4.5mm ball bearing
The letters BB indicate the size of the shot that is in the shotgun shell.This is telling you that your shot size in the shell is the same size as used in BB guns.
It's heterozygous. Heterozygous is when there is a big letter and a little letter, like Bb. Homozygous is when both letters are the same size, like BB or bb.
It is a size 5. BB x
BB guns originally fired lead shot, in size BB (which is between B and BBB)
6mm
No it's still the same size .175, often referred to as .177
Meant to say "half inch Proof Coil vs half inch size BBB" anchor chain.
The original BB guns used the BB-sized lead shot for shotguns, midway between B and BBB size.
With VERY FEW exceptions all BB guns use the same size BB .177 Caliber.
6mm