Here picture of the 8ga from back. This action will also
do 12ga FH, 10ga, 700HE, 600NE,50BMG,etc. The breech
block in this and the 4bore are 1 inch thick front to back,
with the width different. The bottom of block is same on all
and uses same linkage and lever; same hammer and trigger.
The 4bore one will do 20mm, as that is what I make
the 4bore brass from. When I do 2bore, breech block will use
same design, but just be wider on the top of the block.
The recoil pads are over 2" thick. I made the stock
from a 2.5" thick blank......mostly by hand.

This action will hold much more pressure that the heavy
built plastic 8ga cases can take , and they are good
to over 20,000 psi. Like a 1000gr at 2500.Ed
[Linked Image]

Ed Hubel