OK - first, I'm sure you meant that the rifle really FELT as though it might double. But of course, it never actually did this. If it had, there might be agencies out there that would become upset about the situation... :)
Now - your reallywant to know who made the trigger group you have in this build. Unload the rifle, remove the topcover & bolt carrier, and see if it says "Tapco" on the side of the hammer. Even if it does - you won't be sure that all three parts (hammer, trigger, and disconnector) are Tapco G2s.
So - best advice? I would buy a brand new Tapco G2 fire control group. Regardless of how your rifle is set up now, I would get a DOUBLE hook group - three minutes with a file will allow you to use this in a SAR, Bulgy, '47, or '74... and you will be much happier with it :) In my poor experience with several SINGLE hook G2s, I have seen a marked tendency for these to double (in other people's guns, of course). The DOUBLE hook does not do this. Comparison of an original Bulgy Single Hook trigger with a Single Hook G2 will show you why - the Single Hook is just a Double Hook with a leg cut off.
Now - before I get roasted by all Single Hook G2 owners... the preceding is just an opinion. Your milage may vary. Contents may settle on shipping... do not eat.