I have three sets of RCBS shell holders that will not fit my RCBS hand primer, I have one set that will, I can modify 2 of the other 3 sets to fit.
Shell holders are "universal" in the idea that they fit all reloading presses with slotted rams. Outside of that... the dimensions are quite variable and their usefulness in certain tools ranges from questionable to "not even close".
Franken Mauser, I find some good in all shell holder brands, the shell holder is a tool, I am not interested in the color or brand, I use shell holders, I do not talk about using them.
If I measure the deck height and find the deck height is .125 I am not surprised, there was a time when reloaders on the Internet claimed it was necessary to use the matching brands as in RCBS dies with RCBS shell holders then they qualified that assumption with something that came after ‘BECAUSE’, and I did not buy that.
But, on the outside chance I find a shell holder that does not have a deck height of .125 I know how to deal with the difference, this stuff does not run me into the curb.
Again, I purchases a #6 Redding set of competition shell holders for $5.00 dollars, I measured the deck height for each, two were correct, the three in the middle were off by .001 thousandths each, even that did not lock me up, for me is is a simple matter of filling in the blanks, or I could use a standard RCBS shell holder to do anything a set of competition shell holder set can accomplish.