I'm testing 07/21 and I took FL2 and also got a 508. When I checked the questions I got wrong, I was frustrated by the fact that several of those mistakes were from from poor reading skills or careless mistakes; a majority of them were not even from lack of content knowledge! I also realized I didn't pace myself appropriately and ended up rushing the questions towards the end, mostly in C/P and B/B.

There's a user named the_nokia_guy who made a post on a "semi-comprehensive guide" to studying for the MCAT in 3.5 weeks. It's deleted, but if you search for it on google and read the cached version, he says that FL2 is the hardest it'll ever be, and that FL1, the test you should take after doing FL2, will most likely be ± 1 your score on the actual MCAT. Obviously, you shouldn't take his post as divine advice, but I guess it may suggest that your FL1 score is a better indicator of your performance on the actual test.

As for me, I haven't done FL1 yet but I'm reviewing the heck out of all my AAMC material and P/S terms so I can treat FL1 seriously and do it in a less rushed manner. So, all in all, if you're absolutely cynical, this comment instilled a fake sense of calm to you. But, if you found it comforting, I'm happy for you.