Distance between two diametrically opposite grooves
B
Distance between two diametrically opposite lands
C
Distance between two diametrically opposite lands and grooves
D
Ratio of the length and width of the barrel
High-Yield Explanation
The synopsis of forensic medicine & toxicology ; Dr k.s narayan reddy ; 28th edition ; Pg.no. 122 It is also called gauge . Also refer fig 8-16 (cross section of a rifled barrel)