I agree with the above. Most of my documentation for the Forster dies states that a bump of .001 to .002 is typically obtained (FL&NS). Firing pin and ejector removed from bolt. I am not using virgin brass. Once fired. Brass wet tumbled and it’s beautiful. All bump measurements after cleaning are within .0005. I have also watched numerous videos and viewed may posts describing the similar method, but most are on custom chambers, mine is factory.In the old days before bump gauges, reloaders used the rifle chamber as a gauge to set the F/L die for optimum sizing since the F/L die mfg.'s instructions often resulted in oversizing. The process involved incrementally sizing until the case fit the chamber.
With the firing pin assembly removed, the idea was to size to the point where the bolt offered some slight resistance (an approximate 1/2 to 3/4 bolt drop) with the casing chambering and extracting without difficulty. But not a "free bolt drop" because the amount of "free drop" was too difficult to assess and often resulted in over sizing.
With the development of bump gauges, a better and more precise way was offered to set the F/L die. Lots of good advice in prior posts so I won't repeat but you should not have to bump the shoulder back that amount to obtain optimum sizing.
The clean, unsized, deprimed brass I mention above takes a slight effort to chamber.
I think I am going to get the marker out as described in earlier response and see what is hitting. I think I’ll load a small batch at a .002 bump and see if more firings change the profile to match chamber.