My current fort has a lot going on, and every time I load it up I get consumed with making the pump stack for the entryway flush tank, or assigning dwarves to burrows so that the marble transported south by my catapults doesn't get hauled back north to the catapult feeder stockpile. I have poor impulse control, and so it's easy to get distracted from marksdwarf testing.
To test out what people have shared, I made a new embark, set up some stockpiles, farms, and a still, and then concentrated on marksdwarf training. To me, it has never made sense that there has to be a large, overlapping barracks designated from an armor stand or weapon rack, so for the first test, I left this out.
Quivers, crossbows, bolts, archery targets, squad... check. But nobody is moving. It turns out that I'd assigned my miners to be the marksdwarves, and they would run to their stockpile with the Pickup Equipment job-- then get there, get confused, and go back to the dining hall without swapping picks for crossbows. I never figured out how to get them to drop the picks, so I dropped them from the squad and chose two others instead.
Once I'd made enough bolts, I activated the squad to their training schedule, and voilą! Lots of shooting. Until one guy was out of bolts, and the other was down to 10. At that point they went back to standing around in the dining room, complaining about Soldier (Cannot Follow Orders).
So, I've edited the known-good method, and once I've produced more bolts, I'll upload a save so that anyone who is having trouble can compare their setup to mine and hopefully find the problem.
There's still more science to be done, though. Please continue to ask questions and make contributions, and in particular point out any issues or ideas that you think would be a good addition to the Ultimate Marksdwarf Training Guide.
I am a new player, however the other night I set up my first military squad, which happened to be archers, and I had them successfully training in my archery range. ... If you are interested, you can download my game here: http://www.chevrie.com/df-mil.zip.
Thanks for your help Finn. I'll take a look at your example later, and add any info I can glean from it to the Known-Good Method post.
FYI, If you look in the earlier posts in this thread, I made a step-by-step on how to share your save file. You can use that to reduce the file size of your uploads in the future.