Blu Falcon
Super Freak
Sections from the script. I think they gave some of Hudson and Wiezerbowski's lines to Frost.
I do remember him saying "rifles slung" so I would assume Gorman is referring to any type of rifle fire.
Just as troubling of course is that every trooper had a pistol IIRC.
I think Cameron had to work hard to disarm the Marines. Even if Apone was told to collect magazines
1) Would he really do it? Despite what movies might say, in a combat scenario, many people will ignore what they consider a suicidal order. There's a good chance, under those circumstances, that Apone would have withdrew his squad at that point to reassess the situation. Young lieutenants typically give lots of room for their veteran sergeants to also have a say in the decision making process in combat situations.
2) It's not like each soldier would only have one magazine. In real life, every soldier would have carried several spare magazines and once Dietrich and Frost got hit, everyone would have reloaded with their spare mags and continued the fight. Like you said, they didn't know that the core might rupture.
3) Every M41A had the over/under 20mm grenade launcher. Every surviving soldier would have, in desperation, used those grenades.
4) Apone, being a seasoned combat veteran, probably wouldn't have waited to get his troops to retreat. Then again most were dead by the time he asked for orders.
In real life, I believe Gorman, Apone and Hicks would have discussed the tactical situation extensively before they went into that area. Then if they did, they wouldn't have sent the entire combat force. Then again, they wouldn't have left the Sulaco completely unmanned. And even if they went in despite all that, everyone would have had a flamethrower. Grenade launchers can fire a variety of rounds, it's part of their versatility. Even if 20mm explosive grenades were not going to be used, they probably had a buckshot variant available.
Everything about that situation rides the line of implausible. Then again it's a movie and the movie wouldn't have had the conflict it did without that scenario playing out.
Gekko
You seem well versed on the ways of the military.
Considering these are Marines, I would say that the way the scenario played out in the film is very plausible. If these were Army guys, then yes, I'd wholeheartedly agree with your assessment. If they had been Army Colonial Rangers, the plan would have been war-gamed to death, well rehearsed, and had contingency plan after contingency plan to support the "what if" scenarios. The Army spends a lot of time After Action Reviewing everything, or Monday morning quarterbacking after every operation training or otherwise, not to mention the countless control measures implemented to mitigate any unnecessary risk. They take a more precautionary approach to things unlike most Marines I've met or worked with. Not talking bad about the Corp here, but traditionally Marines have been more aggressive about assaulting their objectives without completely thinking things through, as evidence by the you Lieutenant's reluctance to take any advice from Ripley.