several answers to factory choke questions

[whathasn'tbeenused 0]

heres is what i've been able to find out.....

 

Non-American shotguns (12 GA.) normally have a true bore diameter of approximately .005 less than US barrels or generally have a true bore diameter of .725

^this is taken from a chart i found on a few choke tube makers websites and other places around the web...

 

but, i also have a dial caliper that i hope is accurate like it is supposed to be, and i have a saiga 12 and i have all but the paradox choke

 

so here is the rundown of the measurements i've been able to gather and how they compare with "understood" measurements

 

ok, my "cylinder bore" iz109 has a bore that measures .724, this is skeet 1 size in an American barrel

 

my 0,0 "cylinder bore" screw on choke measures up to .722 which is .002 looser than improved cylinder(.720)

 

my 0,5 "modified" screw on choke is .700 which is tighter than improved modified(.704) and looser than full(.694)

 

my 1,0 "full" screw on choke squeezes tight at .679 which is .050 down from a true 12ga bore of .729 and a whole .010 tighter than accepted extra full(.689)

 

i'm reading up on the best ways to pattern a gun and whatnot, and i will follow up very soon with pictures and a good writeup on how the chokes actually perform.

Edited February 7, 2009 by whatelsehasn'tbeenused