Works like a Shultz & Larsen.

https://www.youtube.com/watch?v=WA7wX2lAkSc

I've owned this rifle for a year or so, and I was never confident that I was sizing the brass correctly. Because I didn't know how to remove the firing pin, I worked on a go, no-go method. This was done using a fired Berdan case that would not chamber at all, sizing it fractionally till the bolt could close.

Sized a batch of brass today, and I tested the bolt close on a sized case, compared to a fired case from this rifle, to see if I could feel the difference, and I could not with any degree of certainty.

I had searched online for info several times, unsuccessfully. Today I included 4-lug bolt in the criteria, and Halleluja !

My go, no-go method with the firing pin in the bolt is very close, it needs a partial hair less to be where I want it.