You're right Ken1. Most doubles start from a 20 ga rough forging but machining and heat treatment is different according to rifle pressures. Below is a pic of one of my B25's 12 ga action, besides that of my 9,3x74R double. Its evident that walls are thicker and the bottom is not hollowed out. Also, gas screws are installed to divert gas away in the event of a ruptured case.


André