I'm not a gunsmith but if you go to the Perfect Union website, there is a Mini 14/30 forum that addresses some of the idiosyncrasies of the Minis. Some folks are using 1911 buffers to cushion the slam of the bolt. These guys are die hard Mini guys with a lot of expertise. You may do well to visit . . .
I read about and tried the Shok Buff route and all it seemed to do was shorten the travel of the operating rod / bolt and didn't allow for consistent lock back on an empty mag. Still had the failure to eject problem and the buffs didn't last long.
Honestly, I never realized the gas port was the size of the Holland Tunnel. Corgi's photo was shocking. But that is typical Ruger. They seem to tend to over build to make everything indestructible so it would make sense that they would want to give it enough gas that even the crappiest lacquered up cartridge case would get yanked out of the chamber. And by over gassing it they, maybe, created a different problem.
I carried the M-14 back in the day. Heavy at 9 pounds dry. You knew it when you put 50 or 100 rounds through it on the rifle range. But it ran. And was accurate. And the Mini was marketed as a light cartridge version of that gun.
During 1988 during the Vice Presidential debate Senator Dan Quayle made a reference to President Kennedy. Senator Lloyd Bentson said to him, " Senator, I served with Jack Kennedy. I knew Jack Kennedy. Jack Kennedy was a friend of mine. Senator, you're no Jack Kennedy."
The Ruger is no M-14.
I have no passion for the gun (in general) and no faith in mine (in particular). The only thing it had going for it when it first came out (we had them then in a department I worked for so I knew the old ones) was their price point for a high capacity semi-auto rifle when compared to an AR at that time. Now they are more expensive than an AR and the only thing going for them today in NY is they are not on the bad gun list (for now). I bought it for that very reason, hoping the new models had been improved. I was disappointed but not particularly surprised. Still a Ruger.
But Corgi has given me a glimmer of hope that maybe it can be made somewhat useful. We shall see.