The M41A Pulse Rifle fires 10mm explosive tipped caseless light armor piercing rounds (yes I have that memorized) and is by far the best sci-fi movie gun EVER. I still get a big smile on my face when they fire that fucking thing in Aliens and they just nailed it for Aliens vs. Predator 2. It’s perfect! I can’t wait to kick some ass online!
Special nerd note: Although the M41A supposedly fires caseless amunition, in the scene where Vasquez is crawling backwards through the air ducts firing the rifle you can clearly see cases being ejected. Now you know!