I'm 68 and have been reloading for over 47 years and only once had a rifle that the die would not push the shoulder back far enough. And this rifle was made in Czechoslovakia from a WWII German Mauser action in .270 Winchester with extremely tight headspace. And all I had to do was lap .003 off the top of the shell holder. And I never had a problem with any off the shelf factory rifle and the average die can push the shoulder back far more than needed.
At SavageShooters.com you can always find someone who changed his barrel and used a brand new cartridge case and put two layers of scotch tape on the base of the case to set the headspace. Their next posting is "Help my die won't bump my shoulder back far enough".
In my opinion you see the OP problem on custom chambered rifles far more and I do not blame it on junk dies.
Chambers and dies vary in size and have plus and minus manufacturing tolerances. And once in a blue moon you have a minus chamber and a plus die.
Bottom line, its cheaper and faster to lap a shell holder to increase shoulder bump. And then measure and check to make sure the shell holder is level. And Whidden custom dies has the warning below at their website. So why does Whidden make shorter custom dies, I wonder if they got tired of dies being sent back and having to grind the dies shorter for short chambered rifles.
WARNING
Failure to adhere with below warning could result in damaged and unsafe brass!
The Whidden Gunworks Sizer Die is engineered with a shorter overall length (OAL) compared to other manufactures of sizer dies. This means you can set the shoulder back further if desired based on your specific application. This die is not intended to be used while bottomed out or screwed flush with the shell plate. Doing so will result in the shoulder being set back too far, possibly rendering the casing unusable. During initial setup screw the die flush with the shell plate
then back off 1-1 1⁄2 turns, NOTE: Each full turn of the Sizer is approx. .071” so it does not have to be turned very far to make a noticeable adjustment. Instructions are included with each die set and can also be found at
www.whiddengunworks.com-reloading-dies-instructions.