A bit of a qualifier before I attempt to opine on anything.
I was Infantry for about half of my time in the military. A shooter – usually the designated marksman. If the military has it in inventory, I’ve probably used it at one time or another.
That said, if I were starting from zero today (and knowing what I know) I would tend to side with Selco’s philosophy – use what is found in your area. This means spare parts, compatible ammo and extra weapons/mags (since the guy you just decked won’t be needing his anymore). Whatever you run has to be tough and reliable.
I’m a bit hesitant about going into what I use, but I figure I’m on a list somewhere by now anyway, so why not? Don’t read into this as a “hey, ain’t this sooo tacti-cool!?!”. I invested in what I did because of quality, accuracy, reliability and personal experience with the weapons…
My personal rig is a plain-vanilla HK91. I upgraded the rear battle sight to the latest design (since I judged it to be superior) and also invested in a Bundeswehr-issue optical sight. I’ve cross-trained with the Germans and you can beat a G3/HK91 like a rented mule, and it will shrug it off. It’s designed to run on 147 grain ball ammo, but any .308/7.62×51 in the right bullet weight will make it happy.
My wife’s rifle is a HK93, which is the 5.56mm little brother to the 91. It’s just as tough, and there is some parts interchangeability. I upgraded the rear sight as well, but also opted for an EOTech 512 optical sight for her. It’s easy to use, easy to hit with. It’s a good piece of gear if your shooter doesn’t have a lot of experience. If it craps out, dump it and go back to the open sights.
No lasers, no flashlights on any of our firearms. The HK’s have been dosed with a good amount of camouflage colored Krylon, so they look suitably crappy and are hobo-approved…
Sidearm is a standard GI-issue plain-Jane Colt 1911A1. My wife opted for a S&W 686 in .357 mag. For small game, I have a blued S&W K-22. Small, light, accurate.
Optional weapons include: Winchester Model 12 Trench gun (with bayonet). A Suomi K-31 carbine in 9mm. Precision rifle is a Winchester Model 70 in .30-06, fitted with an ex-Marine Corps Unertl scope. These are being held in reserve for those who we hope will join us when TSHTF.
I was going to write about choosing the correct ammo, but I don’t want to be overly-windy…
The wicked flee when none pursueth..." - Proverbs 28:1