I've only fired it 4 times, on every shot the bolt came loose and the lever actually opened a hair, my smith checked the lock up and it was fine.
After every shot the brass stuck in the chamber and I had to reallty reaf on the lever to get it out. I took the four shells fired and the rest of the box with me when I went over to my smiths and he fiddles around a bit when I was there, he said the same thing you did, lighten the load and it should be o.k. but I don't want o.k. I want to have some faith in it. Both my smith and another smith from the states said that the 284 99C's were famous for leaving the factory this way and can be fixed by meerly redoing the chamber and taking out a thread. Unfortunately I'll have to bring the forearm back a hair as well so it'll meet up with the thread for the forearm bolt.