Hello,

Back to the original Topic,

I looked at the dimensions between the 20 ga and the 12 ga.
I decided that the conversion tubes will not work.
The conversion tube for the 45-70 has allot of meat around the chamber,
this allows a slot to be milled and an extractor to be made.
This extractor is activated by the original extractor in the gun, and just bridges the gap between rims so to speak.
It rides in the slot and is retained by a wire circlip that sits in a groove around the tube.

The 20 ga conversion will only have a 0.030 " thou, wall.
Not enough meat for and extractor of the same style as described above.
One option would be to make a new extractor and fit it after the tubes are installed.
This is possible, but this would make the conversion less than drop in.

I have therefore decided to make a whole gun.
I will have the blanks put towards having a 20 ga SXS gun converted from smoothbore
to fully rifled.
I will keep you posted.

Thanks
Nitro