Half sour pickles do not go bad as long as they remain sealed.
When you have a jar of half sour pickles you can keep them sealed for many years without them going bad but the longer the half sour pickles remain in the sealed jar the more sour they get.
If you open the jar but still seal the half sour pickle jar back up they may go stale quicker but they are still safe to eat as long as you keep them sealed.
If you break the seal of the half sour pickle jar and are not gonna eat the rest of them within a few weeks it's best to refrigerate the leftover half sour pickles in the sealed jar so that they can remain fresh.
Half Sour Pickles go full sour the longer they remain in the jar just like the barrel pickles of many years ago.
Making half sour pickles makes them last longer than regular pickles.
But even regular pickles as long as the jar remains sealed with last 10 years or longer but they may become bitter tasting.