I also had about 350 rounds of Remignton (purchased in 1989) in a G.I. can, it too turned kinda ulgy in appearance but guess what, it fired in the M&P. Now I did have a few more FTF, but over all it did work. We had an elder women turn in ammo from her ( recently passed away husband) to the front of the PD. This stuff was from WWII, 308, 45 cal. 270 mag. It looked like it was at the bottom of Sea for years, 90% shot fine with a few duds to be expected.

There is nothing like seeing a bulk box of sparkle clean 22LR in a mag, as it is unloaded on a Zombie... Watching the golden brass fill up the floor around me makes me feel like I'm coming into gold... Thanks.