I have a TA-11 mounted on a flat top 20 inch upper and have heard that the reticle was calibrated for mounting on the carry handle. I did a search on this topic, and it has been said that the variation in bullet trajectory at longer ranges was "miniscule". Does anyone have more precise knowledge on what the real figures are? Or has anyone tried shooting at longer ranges? Or should I switch to the TA-31? I really like the eye relief on the one I have, but if the reticle is ficticious, why bother to have it?

Yes Sir

I regularly shoot at 400 meters and have shot on occasion at 600 meters.

If your going to switch go with either the TA11F, TA11A, or the TA31F as these are calibrated for the flat top

If you go to www.handloads.com/calc/they have a cool ballistic calculator.  If you enter all the info once with the sight height at 2.5" and again with it at 4" or 5"  you should be able to see the difference in trajectory

Trajectory 2.5" above bore vs. 5" above bore
with 100 yard zero

200yrds   -2.72"  vs.  -.27
300yrds  -12.05"  vs.  -7.05
400yards -29.77"  vs.  -22.27
500yrds  -58.35"  vs.  -48.35
600yrds  -101"    vs.  -88.5
700yrds  -161.97  vs.  -146.97
800yrds  -246.23  vs.  -228.73

Above is based on
Velocity 2900 fps
weight     62grns
sight in   100 yards
Ballistic coefficient  .304
level muzzle
default weather conditions and altitude

That is quite a difference! Thanks!

You might try it again with a height over bore of 3.6" for a carry-handle mounted ACOG. A flattop model ACOG would be even lower.

You aren't going to get an ACOG to sit 5" over the bore unless you mount it Israeli style

God it kills me to see the IMI mounted TAO1's!!! What the heck do they do that for?!?!?!

Bartholomew_Roberts
 
I was just guessing on the 5" above bore as I do not have a carry handle mounted ACOG.  My NSN on the flat top appears to be about 2.5" high

Here is 2.5" vs. 3.6"

200yrds -2.72" vs. -1.62
300yrds -12.05" vs. -9.85
400yards -29.77" vs. -26.47
500yrds -58.35" vs. -53.95
600yrds -101" vs. -95.5
700yrds -161.97 vs. -155.37
800yrds -246.23 vs. -238.53

Quoted: God it kills me to see the IMI mounted TAO1's!!! What the heck do they do that for?!?!?!

bugs me too. i believe it's so they can switch to nvd's and maintain zero. they dont seem to be making pagodas's out of the m4-a1's they've been getting recently.