Dan,
My MOS was not a mortar or artillery but will try and answer your questions as I believe the rules were intended to relate.
All this can be read in the Artillery Drop-In Chapter 10
My question is can I adjust the fire on individual mortars, on the next activation, back to the origingal target location?
[Rule ] When firing indirect, the tubes are fired individually in a similar manner as Artillery Mortars
Based on this rule then follow the below rule...
[Rule] Adjusting Barrage
Yes, you can adjust fire on individual mortars on any activation to any location.
There are two types of "adjustment".
- Less than two (2) inches. The new target location must be in a direction and location that the FO can still see. This type of adjustment will not trigger a re-roll of the deviation dice.
- Greater than two (2) inches. The new target location must be in a direction and location that the FO can still see. This type of adjustment will trigger a re-roll of the deviation dice.
If you "don't" adjust the battery after the first hit and deviation then you don't have to re-roll the deviation dice for a new location. See Repeating a Barrage section. You "fire for effect" and pound that area! <grin>
[Rule] The only difference is when rolling for deviation ... the distance deviated is one-half that indicated on the die.
My interpretation on this sentence is intended for those mortars <60mm. Mortars >60mm are full deviation distance.
Does this also apply to adjusting infantry mortars fire as well when firing indirectly?
[Rule] Infantry Mortars, in game terms, are defined as being 60mm or less and are rarely formed into batteries.
Yes, it does but see the tidbit (above) about deviation dice distance for smaller mortars.
If I'm now firing a battery for the 3rd time, can I correct/adjust the location from where it's currently dropping shells?
Yes, see above
If I fire a battery and it's on target, I roll for each barrel to determine what square it hits. On the next activation, I continue to fire in the same location, do I again roll for each barrel to determine what square it hits?
[Rule] Repeating a Barrage
Yes, you roll a d20 to determine the target square that is hit each time the battery is activated and fired.
When I run a game and a player fires their artillery, I place an explosion marker where the round lands on the template square. Then we adjudicate the hits and damage (if any). The next time the player activates their artillery and choses to leave the barrage marker where it landed last activation, I replace the explosion marker with a shell hole marker showing that a shell exploded at that spot. Then roll a d20 to see where the incoming round(s) for this activation and mark them with an explosion marker.
If the player moves the "barrage" I still replace the explosion marker with a shell hole marker.
You can check out the ODGW gallery to see photos of the explosion and shell hole markers I use in my games. These aren't ODGW marker like the barrage marker or overwatch marker, but one's I've personally bought / made.