The lack of gun knowledge has always been really infuriating in this show, but this last episode (which was already dumb on so many levels) really takes the cake.
--At the range that Negan and his gang were at (looked like maybe 30-40 yards), with that many semi automatic rifles pointed at them, they were dead fucking meat. Nobody would have survived whether they got indoors or not (unless that wall was made of composite armor, rather than drywall and wood). They managed to run in without a scratch on them? Bull. Fucking. Shit.
--The silenced sniper rifles are irritatingly inaccurate.. Any supersonic round is going to be fucking LOUD, sound suppressor or no. You can take a subsonic round (.300 blackout or a big magnum pistol caliber) and make it as quiet as depicted in the show, but if that's the case just how fucking close were those "snipers?" They'd have to be on the roof across the street. Why weren't they helping with the big shootout?
--The "armor" on the vehicles when Rick drove up would be laughably inadequate in a gun battle. Corrugated metal and car parts? Bullets are going to tear through that shit like swiss cheese. About the only part of a car that offers meaningful protection from bullets is the engine block.