Milsurp from a reliable milsurp dealer(Century is not), bubba'd or rebuilt bubba'd rifle?
30" left at 200 is a lot. You won't be able to adjust the front sight that much. Assuming the front sight is centered and not bent or otherwise damaged, itself.
I'd start by bore sighting it. No pricey tools required. Take out the bolt, put the rifle on a flat surface, sight on some object about 100 yards away, then look through the barrel. If they don't match, and I'm guessing they won't, the sights and barrel are off. Next, take the stock off and put a straight edge on it. Looking for a bent barrel. Possible, but not likely. Then look at the indexing. Put the rifle, without the stock, in a padded vise. Use a 6" level on the charger guide to get the rifle level, then put the level on the flat part of the chamber or on the front sight wings. That'll tell you if the barrel is canted and, therefore, not installed properly.
"...Move the front sight ~.135" left...." Absolutely not. Front sights get adjusted in the opposite direction you want the group to go.
Headspace OK? Nothing to do with the sighting, but check that first if you haven't already.
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