[Unclenick]

That extra 0.020" is about the length of a typical freebore. I think the chamber reamer may have been a little worn and cut that freebore too snug. If so, it can be fixed with a throating reamer. I have had bullets catch a little due to misalignment in the Hornady tool (though mine is the original Stoney Point version, and has a metal rather than a plastic bullet ram), but jiggling has always got the bullet to find its way forward. If this is a chronic problem, size the upper half to two-thirds of the neck in die bushings until it just lets the bullet fall through with maybe 0.001" clearance. Or you could size the top half of the neck in a regular sizing die with the expander removed, then use a turning mandrel to get it back out just a thousandth over bullet size, if you have one that will do that for you. The idea here is to align the bullet straighter going in, but without adding friction. Doing it only to half to two-thirds of the way down from the mouth of the neck will allow the remaining fat part of the neck help center the case in the chamber.

Regarding the length of the measurement, get the case comparator inserts for the Hornady caliper adapter. Measure the Hornady OAL gauge case with it write down the number it gives you. Then measure with the bullet comparator. Subtract one number from the other (which from which doesn't matter as long as you are consistent). This will be a number that makes no sense by itself, but if you do the same thing with your cases when you are checking your bullet seating adjustment progress, you will find that when the numbers match you are seating to zero bullet jump with rimless bottleneck cases and you can then adjust however many thousandths deeper you want it to go to set bullet jump. That is because you are setting how far the ogive of the bullet is from the case shoulder, and since the shoulder is what the case headspaces against, it is what actually determines how far the bullet sticks into the throat of the bore, not the bullet ogive location with respect to the head of the cartridge.

As to the Berger method, their recommended 0.030" to 0.040" are intended for the long ogive VLD bullet shape, as you noted. I like the method but prefer to use 0.020" with shorter ogive bullets as they don't have to set back as far to allow a given amount of additional gas bypass between the time the neck lets go of the bullet and the time it finds the throat.