What Acog reticle for 69-77 grain 223/5.56

Tactical Gear Optics & Mounts
1

Is the General consensus to run the 308 calibrated cross hairs if I will be running heavier 223/5.56 bullets?

2

I wouldn’t use a BDC reticle at all but that’s just my recommendation.

3

Load it up, drag it to the range, and see where the BDC hits. Even if the optic is calibrated for a particular round out of a length of barrel and still have a good variance of POA/POI.

4

IIRC, the .308 BDC iis within MOA of the 77gr trajectory. I am moving away from BDC’s because it is ammo specific. Hold over lines like a mil/MOA is more useful to me. But then again, I wouldn’t be making 200+ yard shots anyways so a RDS is 99% of the shooting that I would ever do in any kind of non-square range shooting.

5

We have no problems running the 556 reticles with a variety of heavies. Like Kain said. Pick your load and learn the actual POI. The reticle is usually pretty close for most the loads we shoot.

6

Thanks for the heads up.

7

69 Sierra Match Kings fly generally close to M855.

INSTRUCTIONS FOR SIGHTING IN TA-01

For a Flattop 16" firing M193:
Sight in 1" high at 100m. You’ll be 0.3" high at 200, 0.7" low at 300 and within MOA until 600 where you will be 10" low.

For a Flattop 16" firing M855/ 69 SMK
Sight in 1" high at 100. You’ll be a half inch high at 200 0.5" low at 300 and under 2" off BDC out to 600.

For a Flattop 20" firing M855/ 69 SMK
Sight in 0.8" high at 100 (or sight in at 60). You’ll be 0.5" high at 200 and then dead on the BDC to 500 where you’ll be 3" high and 600 you’ll be 8.5" high.

For a Flattop 20" firing Hornady 75gr OTM/ 77 SMK
Sight in at 50 (or 1.2" high at 100). You’ll be 0.5" high at 200, 1.5" low at 300 and within MOA to 600

For a Flattop 16" firing Hornady 75gr OTM/ 77 SMK
You’ll have to sight in 2.2" high at 100. You’ll be dead on at 200 and 300; and MOA out to 600. On the plus side, your close-in holdover will be a lot less.

A TA-01B with the 7.62 BDC will generally track 77 SMKs from a 16-inch barrel.

8

I went through this a few years back. After conversing with Trijicon, I was informed by them that the accuracy variances seen when using the BDCs for loads or barrel lengths other than those specified by the design of a particular ACOG will only vary about the thickness of a stadia line. My case was the use of the TA01NSN (designed for a 14.5" barrel and the M855 round). I was curious about the difference in the use of a 16" barrel, as well as if I chose to use other loads.

If you should chose to get an ACOG, just get one with the 5.56 reticles. I am partial to their TA11-J and the TA01NSN.

9

Yes, the 308 reticles match typical 77 grain loads almost perfectly.

Conversely if you have a .308 and you only shoot surplus/147 grain, the 5.56 carbine reticles are a near perfect match for that trajectory.