ACOG BDC reticle measurements

[JSantoro]

If you're using G7 you need to use a BC of 0.151 for M855...at least according to the data I have.

I keep seeing .158, but I wouldn't argue anything besides the fact that, given the accuracy waivers M855 is currently being manufactured under, a .304 BC is hopelessly past-tense info.

The reticle "recipes" worked reasonably well for their intended users when the ammo was consistent, but they went and decided to mistake movement for progress, and thereby added an extra chromosome to EVERYthing.

....and then it became relatively common for up to 5 different 5.56 loads to be available to any given unit....*sigh*

[ICANHITHIMMAN]

Listen man, no offense, but every single set of numbers you've posted in this thread have been way off. Don't know it's your software, bad input, or what, but nothing you're saying is making sense. I would either figure out where you're going wrong or trust my numbers. Anything else is a waste of time.

Im using the numbers you posted and shooter , and exbal thanks for trying to brake it to me easy.

I ran it with the G7 and the G1 draq tables with both BC that you listed. I used a MV of 2900 FPS and took bullet measurements with my caliper to ensure accuracy.

What is so off about it to you? It the same software I use with my handloads in my bolt guns and it has allways proven to be right on for me.

[ICANHITHIMMAN]

Guys I'm 99% sure that a .304 BC (G1) is what Trijicon uses. A .304 G7 is definitely not correct, and a .151 G7 is also not meshing with reality. Evidence of this is in the OP's hard measurements of the ACOG's subtensions and my own data, both of which closely align with around a 19 MOA drop at 600M.

Allright I just went back through all my numbers did some reserch. If I use a BC of .304 the G1 drag model and a standard MV of 2970. I get from a 100m zero to a 600m engagement +5.6 mils or +19.2 moa.

[Jippo]

5.56?

Yes, TA11 is 5.56x45/.223Rem reticle.

It should be noted that reticle works as advertised when the rifle is zeroed at 100 meters so that the bullets are hitting the top edge of the donut, that is 1.9MOA over the centre of the inner ring.

[QuietShootr]

Yes, TA11 is 5.56x45/.223Rem reticle.

.

Mine's not.

[Jippo]

What bullet was used to calibrate the ACOG scopes?


The TA01, TA11, & TA31 (.223) were designed for the 5.56mm, 20 inch barrel, 55 grain bullet, and M16/AR15 carry handle mount. The TA01B & TA11C(.308) were designed for the 7.62mm, 20 inch barrel, 168 grain bullet, and M16/AR15 carry handle mount. The TA01NSN was designed specifically for the US Special Operations Command SOPMOD M4 Carbine. To meet their requirements, the reticle bullet drop compensator and range finding stadia lines were based on the trajectory of the 62 grain bullet from a 14.5 inch barrel, flattop mount (Picatinny rail Mil.Std.1913).

Funny thing is that according to my ballistics program 14,3MOA of Trijicons 600 meters matches really close to actual values of M193 at 500 meters. I don't know what to think of that.

I shoot my trijicon with 7.62x39 and 7.62x51 so it really doesn't matter to me as I have to calculate new distances anyway. Reticle does match .308 10g Scenar nicely, btw.

[Jippo]

Mine's not.

Then yours must be TA11B, C or E.

[QuietShootr]

Funny thing is that according to my ballistics program 14,3MOA of Trijicons 600 meters matches really close to actual values of M193 at 500 meters. I don't know what to think of that.

I shoot my trijicon with 7.62x39 and 7.62x51 so it really doesn't matter to me as I have to calculate new distances anyway. Reticle does match .308 10g Scenar nicely, btw.

Mine is none of those. It's a TA11H-308. It's an M240 reticle.

[QuietShootr]

Then yours must be TA11B, C or E.

Nope!

[R0N]

in MOAs