I would not grind away to much, a slight amount of rubbing probably isn't bad as long as you keep it lubed, My fear would be removing too much such that it floats too much and could end up tipping and pinching.
The cheap thin metal on they use on the hulls now will do that occasionally, they bulge too much because they are too hin then they tear upon extractions for the same reason.
I have not noticed that type of wear on the ejection port of my 930, but I use it primarily for hunting so might not have enough rounds through it to see it yet.
If you get this thing running flawlessly you may be getting a call from JM himself wanting one. LOL
The cheap thin metal on they use on the hulls now will do that occasionally, they bulge too much because they are too hin then they tear upon extractions for the same reason.
I have not noticed that type of wear on the ejection port of my 930, but I use it primarily for hunting so might not have enough rounds through it to see it yet.
If you get this thing running flawlessly you may be getting a call from JM himself wanting one. LOL