Question on movement Options

[DarkShade]

I have a question on movement, and initiative.
say you roll initiative 23, have a quickness of 9, a max run of x3, no athletics skill.
you can then run 27 m in one full turn.

you have only a sword and an enemy with a gun sitting 26 m from you, he rolls initiative 12.

will he be able to shoot you before you slice into him?

canon seems to imply that you move the 27 m over the entire combat turn so you will reach the 27 m mark at initiative 0 when the round ends, <meaning in this situation the guy would shoot you once perhaps twice before you got there>
If you just use actions the situation becomes difficult to visualize.. ie in 23 you run 26 m to the enemy then in 13 you chop him up before he can shoot.. but then why cant you keep moving in 13 and in 3?
in games where I have played we have always assumed an initiative drop by movement "getting there takes time" but I would like to know if there is a better way to handle this..

DS