May be Ford, but let me post a few things:

0 = 10 gauge
1 = 12 gauge
3 = 14 gauge
4 = 16 gauge
5 = 18 gauge
6 = 20 gauge
7 = 24 gauge
8 = 28 gauge

C 1 = 9.3X82
C 2 =
C 3 = 8X72 Brenneke
C 4 = 8M. - Mod.88

I'll look for others and the calibres may change over time?

Have to get the order?

8.15 X 461/2 Normal

8,1 x 72 Collath

9,3 X 65

9,3 X 72

9,3 x 80

9,3 x 82

11 x 65


Advert showing Collath 1 gauge & 4 gauge in his gauge scheme.


Lancaster's contribution from NE

http://doublegunshop.com/forums/ubbthreads.php?ubb=showflat&Number=193971&page=3

Kind Regards,

Raimey
rse