I got an FN not long ago, it had been running great. I got the lifter back from C-Rums not long before the match and only ran a couple boxes of shells through it to test it, apparently that wasn't enough to test well. I was getting about 1 failure to feed per stage. I still have to play with it and find out what's going on, my guess is the crimp on the shells, but having fresh mods makes you question your gear. My squad had about 15 shooters and I didn't see many other malfunctions. My observation- don't mod guns right before big matches.
I shot an Improved on 1 stage, and ended up just running Mod on everything else because of the no-shoots.
And yeah, you have to aim.