ACOG replacement reticle

[atek3]

I like the ACOG reticle on the TA11E, however if you are shooting a cartridge with better ballistics such as .26 grendel or 6.5x55 swiss, the BDC won't be spot on anymore. Can anyone take an ACOG and replace the reticle with one calibrated for a different (and unusual) cartridge?

atek3

 

[Zak Smith]

I've never seen anybody offer that service.

I know JP Enterprises got Trijicon to build them a special version of the TA01NSN with a simplified reticle calibrated to a 75/77gr from a 20" barrel at 2000' elevation, using the proper sight-axis-over-bore-axis height. I don't know what their deal was.

Shooting .308 or 6.8SPC or the heavy .223's, you're only like 5" low at 400 yards from the BDC of a TA11/TA31 anyway. Not terribly bad.

-z

 

[Jeff White]

Trijicon will replace the reticule. I don't know if they would make one custom for you, but they will replace their standard ones. I have a very old TAO-1 that has a dot in the center of the duplex. It was supposed to be for CQB use, but with the 4x magnification it was no faster. Trijcon changed the reticule in the next version to a straight duplex. I contacted them a couple years back and they offered to do it for $132.00. She recommended I wait until the tritium lamp needed replaced. You might contact Trijicon.

Jeff

 

[atek3]

thanks for the replies. Do you think if enough shooters (AR-15.com, THR, and others) got together they might add one of the 'new fangled' cartridges to their list of reticle choices? I doubt it, too much bickering about the specs (.26 grendel from a 16" barrel, 6.8 SPC from an 18" barrel, 260 rem from a 20" barrel, bullet weights, BC's, I guess it would be too complicated )

atek3

 

[Zak Smith]

6.8SPC from an 18" barrel should be within 1" of the .308 reticle out to 600 yards.

 _BC_ _MV_         0     100     200     300     400     500     600 | YARDS
0.243 3250 >   -3.43    0.75    0.65   -5.23  -18.72  -43.00  -81.66 | > 20" ACOG STD TA01
0.398 2700 >   -3.42    1.56    0.90   -6.62  -22.21  -47.97  -85.52 | > 20" 7.62 NATO TA11C
0.365 2800 >   -2.53    1.85    0.92   -6.58  -21.91  -47.28  -84.50 | > Hor 6.8mm 18.0"
0.362 2725 >   -2.52    2.05    0.99   -7.05  -23.47  -50.66  -90.62 | > SMK 77gr 20"
0.362 2688 >   -2.52    2.15    1.02   -7.29  -24.24  -52.32  -93.60 | > SMK 77gr 18" GUESS
0.395 2688 >   -2.52    2.09    0.99   -7.05  -23.27  -49.83  -88.41 | > Hor 75gr 18" GUESS
0.395 2725 >   -2.52    1.99    0.96   -6.82  -22.53  -48.26  -85.61 | > Hor 75gr 20"

-z

 

[atek3]

thanks a lot, what program did you use to calculate that table?

atek3

 

[Zak Smith]

atek3,

No problem. I use my own program, a heavily modified version of "smallbal" which is just a "C"-language driver for a G1-G8 (+1909 +Mayevski) differential ballistic calculator. The raw output is massaged into useful form by a Perl-language wrapper.

An old-ish version is here: http://apollo.demigod.org/~zak/geek/public/zak_ballistic.tar.gz but there is no documentation and it is not for the faint of heart.

-z