I wonder if a buffer would mitigate that problem. Or a stronger drive spring? A Wolf spring perhaps? Or would that problem only exist in a pistol such as the M92 or a SBR, and not a rifle? I know SBRs have more gas pressure at the muzzle, but I don't know how much. I recall someone writing about how he drilled down into his gas block, thread tapped it, and installed a set screw inside so he could shoot his SVD suppressed.
How bad are the rivets? I only have 500 rounds through my VEPR (all suppressed) but I wonder how many thousand rounds it's going to take before it becomes an issue.
I made my silencer overbore by about 4 mm. The exit end cap is 12 mm and the last few baffles are about the same (very wide compared to commercial designs. I did that deliberately to mitigate the gas situation. Judging by how dirty my AK is after shooting, I know I still have more pressure and more gas coming back into the action than I would without a silencer. The sound reduction is still good. I was surprised how well it's working since the baffle holes are so big. I think total volume is the most important factor though.