OK -

150 gr.  .308 FMJ (L2A2 British, to be specific)

I sighted my M1A in at 200 yds (15 clicks up from bottom) and seemed to be pretty well zeroed out.

But that was a year ago. I don' think I changed my sights since then.

So i decided to test my zero last nite at teh house. I'm about 6.25" up at at 50 yds. (thats all the room I had to work with)

Can anyone tell me where I should be at 200 yds??

Does anyone have any trajectory tables that could give me  a good estimate??

I'm shooting a match this saturday, and will only get two sighters off before we shoot for real.

4.6 cm above the point of aim at 25m will give you a 250m zero.  If you can zero it at a closer 25m for 250m, then back the sights down to 200, you should be set.  

I'll try to find more, but I don't have much.

Ross

btt

If you're a couple inches high at 50, you're first sighter will be in the black at 200, certainly close enough to make a slight adjustment and put your first shot for score closer than you can likely hold.  I'd dare bet it would put your first sighter in the ten ring on a standard target, if you do your part.

Celt -

thanx.

Here's what I've found so far -

General consensus is that 2" high at 100 yds will get you zeroed at 200 with 147 gr ball ammo.

Right now, I'm 6" high at 50 yds. THERE AIN'T NO WAY .308 is gonna drop from 6" high at 50 to 2" high at 100.

Conclusion: I've got to dial my sights down by 6 to 8 clicks, to make sure I'm on the page.

Then, like you said, I can go from there.

Garandman - here's a link to a free ballistics
program you might like.

[url]http://www.huntingnut.com/pointblank.html[/url]

You're welcome.  In 20 years of NRA hipower I've gone to the 600 yard line many times with maybe a new rifle or new sights, and no better zero than the old "up 3 at 300, 4 more at 400" etc.  Unless you have a really weird load, you can almost always drop the first one in the scoring rings with just the theoretical trajectory in your head...then you have to know what your sights do.  It's more important to know how far a click on YOUR sights REALLY moves the POI.  Once you know that, it's all simple math.
Hold 'em hard tomorrow.