Its more like the die is not bumping the shoulder back, you can set an FLS die up so it acts as a body die but its a fair bit of jiggling around to get it correct don't ask thats why I brought body dies anyway as an experiment grab some old cases and play till the empty chambers nicely but heres the catch. Start with the FLS just touching the shell holder and when you do resize ensure you do not short stroke it flull throw every time and little adjustments, what I did to my lock and load hornady press on the FLS station I center popped 8 points equally so the adjustment are either an 8th or 16th by going in between the marks.
All brass is not equal so go with the ones that last the longest and use that as the base because some *brass have thicker necks and so on and stick to that brass as once the die is set up it should theoretically never change but yeah start with the die before buying the Hornady gauges yeah I have all of them as well don't ask why just OCD at building the best ammo I can for 1/2MOA cartridges