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Thread: TA31RCO-M4CP ACOG holdovers at closer ranges.....

  1. #1
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    TA31RCO-M4CP ACOG holdovers at closer ranges.....

    Indoor range today to record holdovers at close ranges 25 yards and in with the TA31RCO-M4CP
    I'll take these.....for now




    Once the ACOG is zero'ed at 100, the BDC(bullet drop compensator)should be accurate out to 800(for elevation only-windage would be done utilizing the horizontal dashes on the sight(as shown in the very last pic).

    15 shots....3 at each range:

    @ 25Y, hold was at the 300M post

    @ 20Y, hold was just below the 400M dash(around 410)

    @ 15Y. hold was just below the 500M dash(around 515)

    @ 10Y, hold was just below the 600M dash(around 625)

    @ 5Y, hold was at 750M





    From the ACOG book......edited.
    [IMG][/IMG]
    [IMG][/IMG]


    *updated..... @50y hold is at the 200M bottom section (not the tip of the ^ but the inside top part.....the "crotch" as JSantoro calls it) of the Chevron reticle
    Last edited by xbmxracerx; 09-09-11 at 13:02.

  2. #2
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    That's more or less correct. When teaching Marines, we'd refer to the 200m aimpoint as the "crotch." Describing it as a "lower apex" or anything like it often resulted in a tilted head and a Scooby-Doo noise.

    One should never underestimate the power of bathroom humor to get a point across.
    Contractor scum, PM Infantry Weapons

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    Quote Originally Posted by JSantoro View Post
    That's more or less correct. When teaching Marines, we'd refer to the 200m aimpoint as the "crotch." Describing it as a "lower apex" or anything like it often resulted in a tilted head and a Scooby-Doo noise.

    One should never underestimate the power of bathroom humor to get a point across.
    Never thought of calling it the "crotch"....too funny!

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    I'd consider moving away from using the BDC for holds at closer distances, and instead memorize approximate come-ups for the red part of the reticle: I'm assuming that at closer ranges speed might be a priority, and I have MUCH better luck with this: it ranges from about .5" to 1.5" offset from my POA to POI (using either the crotch or the top of the red post, depending) from 10-25yd, with a little variation, and within 10yd I'm aiming nearly a full 2" above where I want to hit.

    At the closer ranges, assuming you're not having any sort of difficulty with using both eyes through a fixed 4X optic (most do), the changes between using a fixed reference for the POI shift, vice trying to keep track of what angular change should be made just started to get complicated, so I just pick an amount on the target, guesstimate it and aim up that far.

    Our Table 3 shoot, which is just drill and kill on reticle holdover once the other marksmanship basics are locked on, still throws a ton of people off. Why some can't figure out that the POI is going to be different from 36m and 6m is a mystery to me, but once I explain to them to just aim at a new location a memorized distance up, they can actually put the head shots into the T box.
    عندما تصبح الأسلحة محظورة, قد يملكون حظرون عندهم فقط
    کله چی سلاح منع شوی دی، یوازي غلوونکۍ یی به درلود
    Semper Fi
    "Being able to do the basics, on demand, takes practice. " - Sinister

  5. #5
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    quick question

    Im new to this forum and new to "black rifles" in general. Have a DD M4 V3 for about month now. Just put an Eotech517 on it. I THINK I have it where I need to be but have a question.

    My 6-8" groups @205 yards (my range's limit) seem to be zero'd, then at 100yd it's a lil high (less than 1" i'd say). It's about .5" low at 50yd, and 2.5 low at 25yd.

    Inside of 25yards, will it be that much lower than the 2.5" low like it is at the 50yd line like the OP's results??? inside 10yd, could it really end up shootin 6+'' low?!

    I didnt think of shooting any closer than 25yds (stupid me).

    Thanks for your time/input. I love this site and reading everyone's advice.

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    Sight height of that type of optic is 2.755" over bore, and it's physically impossible for your round to be more than that distance below your line of sight through the optic....unless something has gone horrifically wrong with either the optic itself or how it's mounted.
    Contractor scum, PM Infantry Weapons

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    Quote Originally Posted by TehLlama View Post
    I'd consider moving away from using the BDC for holds at closer distances, and instead memorize approximate come-ups for the red part of the reticle: I'm assuming that at closer ranges speed might be a priority, and I have MUCH better luck with this: it ranges from about .5" to 1.5" offset from my POA to POI (using either the crotch or the top of the red post, depending) from 10-25yd, with a little variation, and within 10yd I'm aiming nearly a full 2" above where I want to hit.

    At the closer ranges, assuming you're not having any sort of difficulty with using both eyes through a fixed 4X optic (most do), the changes between using a fixed reference for the POI shift, vice trying to keep track of what angular change should be made just started to get complicated, so I just pick an amount on the target, guesstimate it and aim up that far.

    Our Table 3 shoot, which is just drill and kill on reticle holdover once the other marksmanship basics are locked on, still throws a ton of people off. Why some can't figure out that the POI is going to be different from 36m and 6m is a mystery to me, but once I explain to them to just aim at a new location a memorized distance up, they can actually put the head shots into the T box.
    I hear ya......this was mainly just a verification exercise until I get my SBR......I will have an Aimpoint T-1 on that. I would much rather utilize the ACOG for the longer distances but had so time while out in MI at the indoor range and had the ACOG chart and just documented notes......the guys in the lane next to me were like damn! I've got it down to a quick aquisition to be on target though.....@25 I'm right at the 300m post and as I approach....well, u know the rest.....

    Here is a vid of me shooting an 8" steel plate at 230+y (all I've found out here in PA for now) Want to shoot farther......

    http://www.youtube.com/user/emufreak.../0/rLkMPFYoCZE

    [IMG][/IMG]

    ....also lined up some sporting clays to shoot as well.......


    View from the bench.....
    Last edited by xbmxracerx; 09-10-11 at 11:55.

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    Quote Originally Posted by billybob19606 View Post
    Im new to this forum and new to "black rifles" in general. Have a DD M4 V3 for about month now. Just put an Eotech517 on it. I THINK I have it where I need to be but have a question.

    My 6-8" groups @205 yards (my range's limit) seem to be zero'd, then at 100yd it's a lil high (less than 1" i'd say). It's about .5" low at 50yd, and 2.5 low at 25yd.

    Inside of 25yards, will it be that much lower than the 2.5" low like it is at the 50yd line like the OP's results??? inside 10yd, could it really end up shootin 6+'' low?!

    I didnt think of shooting any closer than 25yds (stupid me).

    Thanks for your time/input. I love this site and reading everyone's advice.
    Just like JSantoro said, sight over bore is the thing to remember.....the closer the target is, the higher you have to aim. One of the things I do from closer distances to show people is while at the 7 or 10 yard line, aim center mass with a T-1(Aimpoint) or Eotech non magnified optic. The shots were low based on POA(point of aim) so I then adjust accordingly and aim higher on the next group and the shots were in the zone selected.

    Updated 2014

    Shot at the left target in the picture with the poa being the center dot starting from 5y out to 25y (5 total shots) and marking the impact at each distance and then applying those interpolated holds to the right target in the picture (1 shot at each distance) .....







    Little chilly out that morning

    Last edited by xbmxracerx; 01-13-15 at 17:40.

  9. #9
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    Thank you guys VERY much for your insight. IT really helps. I love this forum! Im learning a decent amount.

  10. #10
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    @ 25m or under you shouldn't HAVE to utilize the ACOG. In fact I always found it took far longer, for no improvement in accuracy than simply aiming down the barrel.

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