I have a question for anyone who's served?

So my friend brother's friend thinks he knows everything. He believed his recruiter when he said that the m249 was a POS because he has done 2 tours. He also thinks that the FN Scar is the best thing since sliced bread, and that the CH-47 is the greatest heli. I have read and been told that the Scar lost its contract because it failed the field test and that the CH-47 has the highest crash rate because its not very sturdy or well built. To give you an idea of him: His dad and him don't clean their guns besides a field strip cleaning here and there. He also believes that the Scar is the first rifle to have a piston system instead of direct impingement witch i know for a fact is bull ****.