As someone who normally only sights in for a 50-250-yd battle zero for a FAL: where do I start if I want to set the system up to shoot out to the fully-plausible 600 meters the sight offers?

I figure to get started, I should be zeroing for 0.25" below POA at 50 yards with the rear sight all the way down.  Then, take it out to 100 yards and adjust the front sight only to get my POI and POA dead center.  Then, verify at 200, 300, etc with the rear sights on the actual settings.  It seems like I could skip the 100 and just go straight to shots at 200 after proving my 50-yard zero is good (and presume I'll be an average of 0.5-1.5" over POA with the rear sight at 200), though; is that a fair assessment or am I being reckless?  

All shooting will be done with surplus ammo, so I don't expect better than 3-4 MOA all day- but I sure would like to have confidence that I have a little better than a snowball's chance to hit man-sized targets out to 500 yards.  

Call me right, or call me stupid- either way, thanks in advance.  

You can start at shorter ranges to make sure you're in the ballpark (I think militaries tended to use 25m tostart before moving to 200), but zeroing on the tangent rear sight was done at 200 metres (or 200 yards for certain rifles, like U.S. and Irish contract rifles, which are calibrated in yards, although this is not relevant to DSA rifles).  If you're on at 200m while the sight is at the 200m position, you'll be on at 600m when the sight is at the 600m position, assuming you have a full-length barrel.  Using a short or super short or 16" barrel could affect that a bit, but probably not so much as to be impractical if zeroed at 200m for the 200m setting.  IIRC, one click on either the front or rear sight changes POI by 2cm at 200m.

Thanks for the input.  Yeah, I have the standard 21" barrel, so I am confident the sights won't steer me wrong.  Shooting at 25 yards/meters at my range is do-able but annoying; I suppose if I can shoot there for an exact POI to the same POA though, that'll save me some brain-power...Which is why I am also doing this with surplus rounds.  

I zero mine at 50 yds. with the appropriate offset (1.2" or whatever high) to make sure the sights are on at 200 yds.

So, you mean your rear sight is already set for 200 meters when you shoot the 50 yard group?  And your 50-yard groups is 1.2" or so above point of aim?  Interesting.  That would save me a step in the shooting process, too...

Correct, good sir.

I use JBM ballistic calculator to come up with the drop and windage table.

I have always zeroed mine with the rear sight set at the lowest (200 meter) setting at 25 yards. Then check windage at 100 yards. Currently, this is the longest range I have. You POI should be roughly 1" above POA at 100 yards, and very close to 200 at that distance. I leave it there. In years past when I had access to a 500 yard range, it was amazingly close all the way out to 500 on the rear sight when moved in 100 yard increments. That was/is with an StG58 with a 20" barrel. For shorter barrel lengths, you'll have to do some research.