So in 1e, if a Y-wing (or another ship with the Sync Turret) is firing in it's primary arc. It can modify up to a # of dice equal to it's primary weapon value.. In a Y-wings case 2 dice...

But if i do that, can i then re-roll the same dice if i have and spend my target lock??

You can reroll each die only once.

True for both 1st and 2nd edition

Copy that. A question came up last night, and in a quick re-read of the rules, i didn't see it mentioned... Someone else said that, and i'd thought i would get some other input..

You modify the attack you are using. So if you are firing say a weapon with 4 firepower (say homing missiles) and your primary firepower is 2. You will modify the 4 dice you are rolling because you are not using your primary weapon. When using a sword you don't compute the damage of an arrow or any enchantments on your bow. It is only the sword that matters.

It's worth noting that you'd be able to reroll in two steps.

Reroll first with the Synced, then reroll any dice you haven't rerolled yet with the Target Lock.

Suppose you roll three blanks with Synced Turret on a Y-Wing. Perhaps it'd be best to reroll your 2 dice from the Synced Turret ability first. If you get double-hit, maybe you want to spend your lock to reroll the 3rd die to try for 3 hits. If you blank out again, there's no point in spending your Target Lock.

That was the question the other player had. He rolled 2 blanks and a focus. Re-rolled the 2 blanks cause the target was in his primary arc, and got 2 blanks again. Was asking about whether he could spend the TL he had to re-roll them again. I wasn't sure. But someone else in the room we were in, said "you can only re-roll each dice once".