What are these marks?

[1911LVR]

After cleaning my new (to me) Wingmaster and wiping the outside down with thin layer of oil, I put it away in its hard case. Probably not the best storage solution, but I'm working on it. The other day I opened the case and saw what I thought was fingerprint marks and I wiped it down again and made sure I didn't touch the metal with my fingers. The marks went away.

Today I looked again and the same marks have returned, but I'm not so sure they're actually from my fingerprint oils. The marks looks more square and the pattern is too regular. The other side has similar marks, but larger and irregularly spaced.

Any idea what this is from?

20181208_144743.jpg (131.47 KiB) Viewed 1869 times

[Banshee]

That is simple, its from the foam in the case.the foam is like a sponge and is drawing the oil off of the steel. I wouldn’t store the gun in the case.

[1911LVR]

Ahhh.....that makes total sense now! Thank you so much.