I followed the advice from 45ACP and it solved my problem. Same stock, same rifle. The height relation between the trigger group and stock/bolt was too much. Caused the same issue you are describing, hammer follow.
The solution is easy. First off, you are dealing with a 500/600$ rifle, so I wouldn't worry too much about playing gunsmith yourself. What I did, following 45ACP's advice, was remove a small amount of material from the "tabs" on the bottom of your trigger group; the area that seats against the stock on lockup. Off the two side tabs and the rear tab of the trigger group. Start small, and watch your work with a micrometer to make sure you are taking off the same amount of material all the way around. I used a dremel, and honestly I removed hardly any material. Basically polished it/took the finish off. This eliminated my hammer follow issue. Around 200 rounds since this mod and not a single issue. Its a easy fix, and I dont know about you but I'd rather remove material from a chi-com trigger group than start looking into milling the sage stock.
Another piece of advice I received that is a great idea, but did not solve my issue was lock the trigger group into the stock and THEN tighten up the bolt that holds the op rod guide to the stock. Great idea that may work for some rifles, however my specific rifle required more massaging. Maybe give this a shot before you start removing material from the trigger group tabs.
Best of luck, let us know how you make out.
*edit* there are people here on this subforum that have forgotten more about this rifle than I know. If I missed anything/described something wrong I'm sure the gurus here will steer you in the right direction. Thats what they did for me. Cheers.
