[mrreaganaut]

Hm, I wonder what would happen if the grooves were cut to spiral a little bit?

[Vaquero]

Hm, I wonder what would happen if the grooves were cut to spiral a little bit?

only the cylindrical part of the bullet which is only visible in the case in the picture above can engage the rifling to cause spin. the ogive or conical part of the bullet would never touch the rifling hence never impart spin...