While I'm not trading in my AR15's anytime soon, this is a nice discussion on the fundamentals of riflery.  It's somewhat similar to Fred's Guide to Becoming a Rifleman:

Becoming Riflemen

If you can't score 210 on the AQT course of fire... then its time to work on these skills.

AR15's shoot best off the magazine, so unless you've got a free-floating barrel, I don't recommend putting much pressure on your AR15 sling

Got my rifleman badge in 2009, disappointed in how many people showed up with scoped rifles and could not qualify it's only 25 yards so I used a 10/22 with Tec sights.  I routinely shoot irons at 200 yards (longest distance at range), would like to do eat at real ranges maybe next summer vacation, got bored with ar15 but been thinking about revisting them still like the m1a and garand.

Snowman357

In my experience most shooters do not have solid zero, nor can they reliably hit beyond 200 yards with a rifle.  That said people that compete or do a lot of shooting can hit Rifleman on the first go around.

Known-Distance Appleseeds are the next step after doing the 25 yard AQT.  It's the real deal using centerfire rifles out to an actual 400 yards.