This question always raises the same cut and paste shitstorm.
Taking the question for what you've put into it, and assuming you've already got your food warehouse stocked and your bunkhouse furnished, your walls up, and your schoolhouse well provisioned.
The peasant troops of many communist insurgencies have been managed to kill thousands of people with minimal training using the factory sights on those things. Which, by the by, are a pretty close match for most of the earlier sights you'll find on the classic bolt and lever guns, which have been taking game and killing people for going on two hundred years.
If you're passing out firearms to untrained people, you're better off not trying to teach them long range marksmanship with all the calculations that entails. Concentrate on teaching them the battery of arms and using the iron sights at reasonable ranges. After that, if any of them show any particular aptitude, you can skip your ass over to the gun safe and unlimber some glass for them.
It's easy to get caught up in the high tech world of modern warfare and forget that riflery, at it's core, ain't that hard.
Here's a thought. If you're planning on handing out rifles, invest in the time and minimal cash and become an Appleseed instructor. That way it won't be an issue.