NUMBERS - NUMBERS - NUMBERS
 

Today I brought home some calipers from work so that i could take some measurements of my 12ga hammer. I'm hoping some of you experts can shed some light.

First of all the chamber length:
2.565" to a definate ridge line inside the barrel.
Does this mean its chambered for 2 5/8 shells? 2 3/4 fits fine.

Barrel Length:
28"

Right barrel at muzzle: .712 - .707
Left barrel at muzzle: .72 - .716
What does this say about the chokes?

Sorry, calipers will not measure your bores. You need a bore micrometer as sold by Brownell or Galazan. Price $100 to $125,

Bore gauge.
http://www.brownells.com/.aspx/pid=1...GUN-BORE-GAUGE

Wall thickness gauge.
http://www.brownells.com/.aspx/pid=2...HICKNESS-GAUGE

If a research paper is available that may also tell you the chokes. I was suprised to find that my 16 guage had both barrells at full choke. I always thought the left was full and the right was modified.

CHAMBER LENGTH
 

Thanks for the links, what about the chamber length. Does this indicate what type of shells it was designed for?

That is a nominal 2 1/2" chamber. You should probably shoot 2 1/2" shells in those chambers, especially since the chambers have a ridge at the chamber end. Unless you choose to remove the ridge line, paper 2 1/2" shells would be preferred over plastic shells, since the plastic shells are thinner than the paper ones.