It's basically Die Hard in a high school.
You could consider it a pro gun piece in the sense that the heroes solve the problem with guns while showing the authorities and the school personnel as incompetent fools (like the security guard who pisses his pants and afterwards is only seen worrying about changing his pants, to never be seen again).
OTOH, I don't like the ideas it gives to prospective future school mass murderers, like holding hostages as leverage to ensure that censor trigger happy big tech doesn't cut their social media live feeds by threatening to kill students for stopping the live stream. They also used a shotgun to breach locked doors to class rooms and attempted to methodically clear rooms to gather the students and staff to the sit in the cantina by the car bomb.
The shole live stream was also a ploy to delay tactical response and allow them to get as many people next to the bomb, probably to reach a high score in victims.
All sound ideas from a purely tactical (hostile side) prespective. Also, there were many references to Columbine, like the distraction bombs to tie rescue and police to remote locations and also to block major roads to the school. The real school mass killers almost always study past real incidents and also watch movies and other creative content about imaginary mass killings.
I found it extremely odd the initial scene with coup de grace of a deer with a rock. Like WTF? Who the hell takes someone hunting for the first time and doesn't talk in advance about what to do in case of a lung shot? Or thinks it's a good teaching moment to start jabbering about how to kill the pray from short range, instead of doing it promptly and then discussing it?
I know it was supposed to show her as being decisive in a stressful situation and taking unilateral action with the best means available. But someone who knows nothing about hunting will instead think she's the psycho school killer. Not a good juxtaposition either.
I'm not aware of any select fire reproduction version of the MP40. So how is it possible Chris Jelick fired single rounds to execute the students at the beginning of the attack in the cafeteria, yet never deployed the folding stock or ever hit anyone after going cyclic? If you are supposed to be familiar enough with an open bolt subgun to fire single shots with tripping the trigger, you should be able to properly deploy it in short burst automatic fire as well. And the MP40 is such an easy gun to shoot full auto. It makes no sense.
I guess the movie makers' idea is to start it slow and make it look like it's a semi replica, but then up the ante when he starts to spray and pray. Overall, a very strange choice of gun for one of the main antagonists. If someone has an original MP40 to use in a school massacre, how come he is an utter moran who hears sounds in his head? And doesn't actually know how to shoot except single shots?
When Zoe is fighting with Anna Jelick and struggling with the Glock, Zoe intentionally pushes the slide out of battery and so prevents Anna from shooting her in the face. After she kills Anna, she finds that the gun is now empty and Anna didn't have any spare mags. A school mass killer part of a gang armed with full auto weapons, shotguns, revolvers and knives, but doesn't have any spares? Hello? Earth to orbit, do you read me?
The guns in this supposedly pro gun movie were rather horrible McGuffins. And a VERY odd choice for the subject matter of the first DM entertainment venture. Sure, it was fun to watch, but perhaps too edgy. I hope their next one is not going to be about abortion...