40/82

[Kurt]

Both chambers are based on the .45-2.4 cases but there is a difference between the Rhoades and the Crossno .40-82 chambers. The Rhoades has a .400" cylinder ahead of the rim on the base tapered 1.02 degrees to the cylinder neck then .400" to the chamber end.
The Crossno is tapered from the rim to the case mouth length of a .40-65 then a cylinder to the chamber end giving it a longer case neck.
To change the .40-65 to a .40-82 Crossno can be easily done with a throating reamer only. You can even do this using a T handle without removing the barrel from the action with a reamer like this.

You can use this reamer to change a .40-70 Sharps to a longer .40-3.25. I used this reamer for a .40-65 rifle I have that had a bad factory throat and made it a .40-72 to clean up the chamber.
Kurt