Yep, see post #4.
Sorry, missed it, but what's not logical? I believe it's sniper spending time following his target and shoot when appropriate. And as I know you can't rely to get more accuracy for hour aiming against half-hour aiming.As I see that's not "you should spend some time into aiming, so for half-time you get half-bonus", it's just different types of aiming.
It is clear that the rules does not allow you to improve you Aim in the second turn. If you really want to get that +20 to your BS but you also need to spend maybe half action on reload you could do something like this according to RAW (even if its a bit foolish):
1. Turn:
Half action reload
Half action Aim, now +10 BS
2. Turn
Full action Aim, now +20 BS
3. Turn
Half action shoot using +20 BS from aim along with other modifiers
something else for the last half action
It seems a bit silly though, a more resonable approach is:
1. Turn
Half action reload
Half action Aim, now +10 BS
2. Turn
Half action Aim, improving +10 BS to +20 BS (which must be the MAX since Aim by RAW does not provide more than +20)
Half action shoot using +20 BS from aim along with other modifiers
The house rule in this case is that you can spend a half action to improve a +10 aim to a +20 aim. In the groups I play we use this house rule, and I believe a lot of other groups use it as well. It doesn't really collide with anything else in the rule set, nor does it allow for infinite aims.