I shot a match this past weekend and when cleaning my MCOP, I noticed it had a lot of grit that made its way to the interior.... I took it all the way down to clean.
I had a wild hair moment and took a chance on the front strap that has bothered me for years.
While I needed to go a little more, I don't have the right tools (limited to files, sandpaper and DREMEL) and I never ordered the tool to make sure I had ample thickness. So, I got scared and stop short for now.
I used some automotive gray high heat primer to cover the exposed metal and heat treated the paint with a heat gun. I don't know how oil resistant the primer will be... but just looking to keep it from rusting.
on another note, I bought 5 Vickers mags with steel base plates. I don't care for the look of the tapered base plates, but I like the added grip they offered as the older I got, everything seems slippery to me.
When I first got these mags, they would not seat w/o slamming them home. I ran into the same issue with ETMs and aluminum base plates. I trimmed the ETM aluminum base plates, and they work great. I removed about .005" from the steel Vickers plate (they are hard) which got them to seat empty. Put eight rounds and some required extra effort to seat. I likely need to trim more. Also, 7 rounds load easy, #8.... did not. Vulgarity helped with pushing it home, but they functioned well.
I am not sure if my frame is out of spec, or it's just a Wilson Combat thing with clearance and base plates with stops. I took the mags apart to inspect and clean out any grit, those springs are beefy.