TA11 ACOG (Red doughnut .223 reticle) manual?

[michael_aos]

I can't find my manual, and I'm not seeing an online version on the Trjicon website.

As I recall, the top of the doughnut is 100m (109yd) and the bottom of the doughnut is 300m (328yd)

I was thinking the center of the doughnut was 250m / 273yd.

The 3rd stadia-line below looks like it's marked 6, so the previous two lines should be 400m and 500m, respectively.

I seem to consistently have difficulty with targets around 350-400yds, and I'm thinking maybe my zero is off.

Does anyone happen to have a manual handy or recall exactly how the reticle is laid-out?

Also what's the impact of mounting the TA11 on a flat-top -vs- carry-handle?

Mike

[Zak Smith]

Mike,

I have a reticle print somewhere at home. The donut is 4 MOA top to bottom, 2 MOA inside diameter.

The first stadia line is for 400m with their ammo solution.

With the 75gr ammo in my guns, I have to aim the first line (400m) at the top of the plate to make hits.

No appreciable impact CG vs. FT for this application.

[michael_aos]

I think most of my misses were low.

I also noticed a definite tendency to want to push my reticle down (out of the way) to spot my own hits.

I know that was screwing-up my follow-through.

I shot a lot better when I made conscious effort to stay on the target and trust the R/O to call the hits.

Mike

[Zak Smith]

You should be able to see target reaction without moving the reticle.

[michael_aos]

With the 75gr ammo in my guns, I have to aim the first line (400m) at the top of the plate to make hits.

I should sit down and figure out where the 69's or 75's would be out of my rifle.

I was kind of suspicious the wind was blowing my 55gr XM193 off the Larue and popper out @ ~425yds.

Mike

[michael_aos]

You should be able to see target reaction without moving the reticle.

Yeah, I should. I was just doing it wrong.

Especially on the ~350yd flash targets, the red doughnut of the reticle tends to blend in to the orange target. It's probably exacerbated by my red/green color-blindness. I do have some electrical-tape of the fiber-optic to tone down the reticle.

If I'm going to LOOK for hits, I should be looking for the cardboard "flag", and not at the actual metal target anyway.

Mike

[michael_aos]

Does anyone know if the center of the doughnut is supposed to be zeroed @ 250M?

I'm pretty sure it is, but I'd like to know for certain.

Mike

[Zak Smith]

It's 2 MOA down from the top of the donut. Run the ballistics for your load and see.

[michael_aos]

It's 2 MOA down from the top of the donut. Run the ballistics for your load and see.

:mrgreen: I knew you'd say that.

Would you guess about a .243 BC for XM193?

Mike

[Zak Smith]

Yes

[michael_aos]

Trying to work my way through Sierra Bullets Infinity v5.1.

I used Black Hills 55gr FMJ, since I didn't see an entry for XM193.

BC of .243
Altitude 0, 59 degrees, standard atmo model.

With a 250m zero, 100m is 2.11 MOA. Close enough.

But 300m is -1.35MOA.

If I change it to 200m zero, then 100m is at 1.01 MOA, and 200m is at -2.44 MOA.

The numbers don't seem to come out right.

This is with a sight-height of 3.00".

Mike

[Zak Smith]

The zero is the top surface of the donut @ 100 yards.

[michael_aos]

The zero is the top surface of the donut @ 100 yards.

Right, but shouldn't it ALSO be zero again in the center of the doughnut @ 250m?

If I zero @ 100yds, then 250m is -2.06 MOA (close enough), but 300m is only -3.4 MOA.

It really irks me that Trijicon doesn't have the owners-manual online.

Mike

[Zak Smith]

Look at the data.

By the way, SOB is closer to 2.6-2.7"

We aren't at 0' either.

I don't see anything inconsistent with the numbers you posted.

You are confused because you are not plugging in a 100-yard zero and using the top of the donut as the refernce point (0 MOA).

[michael_aos]

Look at the data.

By the way, SOB is closer to 2.6-2.7"

We aren't at 0' either.

I don't see anything inconsistent with the numbers you posted.

You are confused because you are not plugging in a 100-yard zero and using the top of the donut as the refernce point (0 MOA).

I was trying to duplicate their numbers first, then adjust from there. I assumed they designed the BDC based on 0' and standard atmo and with the ACOG attached to the carry-handle.

Mike

[michael_aos]

OK, I was expecting to see 300m as -4 MOA from 100yds. At the bottom of the doughnut.

It's more like ~-3.5MOA from 100yds to 300m. So 300m isn't QUITE at the bottom of the doughnut.

I've notice I'm consistently having problems with the targets around ~350yds - 400yds, and I was thinking maybe my zero was off a little.

Mike

[Zak Smith]

Remind me to find that TA11 print tonight.

[michael_aos]

Trajectory for BlackHills .224 dia., 223 Remington, 55 gr. FMJ at 3250 Feet per Second
At an Elevation Angle of: 0 degrees
Ballistic Coefficients of: 0.243 0.243 0.243 0.243 0.243
Velocity Boundaries (Feet per Second) of: 2775 2775 2775 2775
Wind Direction is: 3.0 o'clock and a Wind Velocity of: 10.0 Miles per hour
Wind Components are (Miles per Hour): DownRange: 0.0 Cross Range: 10.0 Vertical: 0.0
Altitude: 0 Feet with a Standard Atmospheric Model.
Temperature: 59 F
Data Printed in English Units
Range Velocity Energy Momentum Drop Bullet Path Wind Drift Time of Flight
(Yards) (Ft/Sec) (Ft/Lbs) (Lb-Sec) (inches) (1 MoA) (1 MoA) (Seconds)
0 3250.0 1289.7 0.79 0.0 0.0 0.0 0.000000000
25 3145.1 1207.8 0.77 -0.11 -6.13 0.3 0.023459022
50 3042.8 1130.5 0.74 -0.43 -1.59 0.5 0.047703519
75 2942.9 1057.5 0.72 -0.99 -0.37 0.8 0.072767275
100 2845.2 988.4 0.69 -1.8 0.0 1.1 0.098686770
125 2749.7 923.2 0.67 -2.88 0.02 1.4 0.125501345
150 2656.2 861.5 0.65 -4.24 -0.16 1.7 0.153253421
175 2564.7 803.2 0.63 -5.92 -0.45 2.0 0.181988946
200 2475.0 748.0 0.60 -7.92 -0.82 2.3 0.211757628
225 2387.0 695.7 0.58 -10.28 -1.27 2.6 0.242614717
250 2300.8 646.4 0.56 -13.02 -1.77 2.9 0.274618369
275 2216.4 599.8 0.54 -16.17 -2.32 3.3 0.307830896
300 2133.7 555.9 0.52 -19.77 -2.92 3.7 0.342320023
325 2052.7 514.5 0.50 -23.84 -3.57 4.0 0.378157924
350 1973.6 475.6 0.48 -28.42 -4.26 4.4 0.415420803
375 1896.4 439.1 0.46 -33.57 -5.01 4.8 0.454189320
400 1821.2 405.0 0.44 -39.32 -5.81 5.3 0.494548507
425 1748.0 373.1 0.43 -45.72 -6.66 5.7 0.536586623

[michael_aos]

Remind me to find that TA11 print tonight.

I'm going to dig around in the crawl-space for my manual too.

Mike

[Zak Smith]

REFERENCE IS TOP SURFACE OF DONUT AT 0 MOA

INSIDE TOP 0.8 MOA
INSIDE BOTTOM 3 MOA
OUTSIDE BOTTOM 4 MOA

FIRST STADIA LINE 6 MOA (4.1 MOA WIDE)
SECOND STADIA LINE 9.7 MOA (3.3 MOA WIDE)
THIRD STADIA LINE 14.3 (MARKED "6") (2.8 MOA WIDE)
FOURTH STADIA LINE 20.3 MOA (2.4 MOA WIDE)
FIFTH STADIA LINE 27.7 MOA (2.1 MOA WIDE)

DONUT INSIDE WIDTH 2.2 MOA
DONUT OUTSIDE WIDTH 4 MOA

STADIA LINE WIDTH 0.4 MOA

[michael_aos]

Ah, it makes much more sense now.

Thank you.

Mike