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.

That's very much like I remember the one I saw as a kid. Because it was stockless I assumed that it was a parapet gun and remember being properly confused when the elderly gent curator showed me a pic of it or one like it in a punt. Was a bit like the aquatic version of an A10 Wathog, i.e. mostly gun with a bit of transport added.  

He describes how they hunted the ducks and geese - but mostly in winter - because during summer the geese would migrate. So they dragged their skiffs across the ice and they would find rafts of birds in the holes in the ice sleeping. Then they would get the skiff in the water, approach them and fire. He also describes how the Chesapeake retriever and a black Labrador would compete to try and get the most ducks.

It is actually a very good book for outdoors people like I'm sure most of us are. Here is a link. Use it or don't use it.

He has quite a few other books that are great as well. Just a hefty read of around 1000 pages ;) But really worth it.

https://oceanofpdf.com/authors/james-a-michener/pdf-epub-chesapeake-download-69751042164/

Cheers