They are~ just not commonly used anymore~ As far I am concerned blocking bullets and dodging them is allowed since you see that happen in One Piece as well~ I mean even thou they use flintlocks all the way....it doesn't hold em off to shot fully automatically when the manga or anime feels like it XD and so the characters also dodge and slice their way through a hail of bullets~
Looks at the Frankies! They shoot like crazy with a rocket-launcher while they sarcastically loaded one bullet xD

It is OP "lore" so cyborgs are allowed and swords are as well~ 

Just on the side board.
1) good to see you Crimson!
2) i am in fact creating the Cs for the "good" bad guy who uses swords all the way...obvious counter to the revolver swinging bad "good" guy who is already up~