I've had several Nitro Specials including one 20 gauge.
On Nitro specials the choke code is:
4=Full
3=Mod
2=IC
1=Cy
The numbers can be found on the barrel flats. As far as the numbers are concerned, I'm going by memory, someone please jump in if I'm wrong.
On one gun, I used to occasionally have trouble breaking the gun open because the firing pins would drag.
Steve


Approach life like you do a yellow light - RUN IT! (Gail T.)