The first French action I used is a Fusal Robust 16 ga it is very tight and no measurements have changed after being re-proofed and 100 pluss rounds of standard loads. The action I just recieved is a 12 ga Verney Carron and has three bites on the double under lugs and a hidden fastener. It also has side clips and firing pins which measure .82" so it has promise and will probably end up a .470 Nitro, I will try to post a few pictures of the gun.