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M193 55 grain 200 yard trajectory & RIBZ

Discussion in '.223 Remington/5.56 NATO' started by Water Monkey, Sep 4, 2012.

  1. Water Monkey

    Water Monkey The man, the myth, the monkey Moderator Supporter

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    I've been reading up on those trajectory charts listed on this thread supplied by Nitesite:

    http://www.m4carbine.net/showthread.php?t=65679

    Now I zeroed my A4 rear sight to be in line with the RIBZ (Revised Improved Battlesight Zero). Due to the fact that my rear sight is stated at 6/3 I need my sight at -6 for 100 yards and -4 for the 50 yard/200 meter setting.

    My question is this:

    If I'm set up at -4 for the 50 yard/200 meter and based on the charts my far zero point of impact will be roughly at the 225 yard mark. If I'm shooting at a target 200 yards away my impact will be roughly in the 1" higher than where I am aiming.

    What if I set my rear sight at -5.... would that flatten out my trajectory of the bullet and hit better at 200 yards? Or would that have me hit about 1" lower than my point of aim.

    Just throwing it out there as a theory question right now. Haven't hit the range to test the results. Plus getting the 200 yard spot is tough to get.
  2. Rossignol

    Rossignol The Original Sheriff Staff Member Global Moderator Moderator Sponsor

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    I know clue how to answer that but hope to learn the answer!
  3. Water Monkey

    Water Monkey The man, the myth, the monkey Moderator Supporter

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    lol things that I ponder while at work.

    OK I did some quick math since I have time to study the graphs a little better.

    Here's what I'm coming up with (just by reviewing the graphs):

    A 50 Yard Zero M193 bullet will have a trajectory to hit at 200 yards about 1" high from the point of aim. This setting is -4 clicks past 6/3 on my A4 Rear Sight.

    A 100 Yard Zero M193 bullet will have a trajectory to hit at 200 yards about 2" low from the point of aim. This setting is -6 clicks past 6/3 on my A4 Rear Sight.

    The drop point between both settings is a drop of 3". Since it takes 2 clicks between the settings I'm estimating each click drops the bullet 1.5". Therefore at the -5 setting I'm most likely achieving 0.50" low impact from point of aim at 200 yards. I'm thinking this may be the better 200 yard setting for range shooting.

    I welcome any thoughts on this :)
  4. Rossignol

    Rossignol The Original Sheriff Staff Member Global Moderator Moderator Sponsor

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    Well, makes enough sense to me. Gonna have to test your hypothesis, establish controls and what not! ;)
  5. Water Monkey

    Water Monkey The man, the myth, the monkey Moderator Supporter

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    oh yeah plan on it. Probably not this weekend. Running the mossberg 590A1 with some buddies on Saturday during a time when the 200 yard line is basically swamped.

    Now I gotta pick me up a larger bullseye! 200 yards is the farthest I will have shot.
  6. carbinemike

    carbinemike Global Moderator Staff Member Global Moderator "Philanthropist"

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    Watermonkey, good luck when you make it to the 200 yard range and I'll be interested in your results too.
  7. Rossignol

    Rossignol The Original Sheriff Staff Member Global Moderator Moderator Sponsor

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    WaterMonkey, I've never done 200 yards either.

    OH! Real quick! Is your rifle 16"? Also, I believe you said its a 1/8 barrel?

    Gotta know these things, you know, for science!
  8. Water Monkey

    Water Monkey The man, the myth, the monkey Moderator Supporter

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    No prob guys I'll post results. I like sharing real data. It helps me categorize my noob findings :)

    16" carbine with a 1:8 barrel... melonite treated.

    After hours on the weekend the range moves the benches on the 200 yard line and creates a 300 yard range as well..... more messing with numbers may be in order after I find out how she does at 200 yards.
  9. Water Monkey

    Water Monkey The man, the myth, the monkey Moderator Supporter

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    weather permitting I will be at the range this Sunday to hit the 200 yard line to see how she groups at -4 and -5 settings on my A4 rear sight.

    Also have some new mags to test out and have my Gear Sector 3 point sling coming in any day now. Woo hoo

    Will post results.
  10. mko1024

    mko1024 .22LR

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    I don't want to derail your thread but I also found this discussion over on m4c to also be very useful. I don't have an A2 sight on my rifle so I stick with the 100m zero all the time.

    http://www.m4carbine.net/showthread.php?t=107572

    Good luck at the range!
  11. Water Monkey

    Water Monkey The man, the myth, the monkey Moderator Supporter

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    No worries and it's not technically a thread hijack. I actually read that post a week ago. My 100 Yard zero is -6 on my A4 rear sight. I actually sighted that in a couple of weeks ago. So my trajectory will be really close to a 100 meter zero (109 yards). I achieved this doing the RIBZ method.

    This thread is pondering the effects of a 200 yard range target and using the setting between my 50 Yard/200M setting (-4) and my 100 yard setting (-6) by placing my rear sight at -5 and seeing if my POI is relatively my POA as opposed to the other settings.

    In theory my 50 yard/200m setting would have me hitting high about 1" from my POA. And my 100m setting would have me be hitting about 2" low from my POA. I'm wondering if the click between would be the best setting to get my POA & POI darn close :D
  12. Water Monkey

    Water Monkey The man, the myth, the monkey Moderator Supporter

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    Sorry guys it was totally packed at the range all day today. I showed up at 1pm and barely got a spot on the 50 yard. No 200 yard spot to use today so the primary goal wasn't accomplished.

    BUT I got a chance to make sure my new mags worked... Yep

    Got to play with my Gear Sector 3 point sling... check love it

    Did some firing in 3 shot bursts with the 3 point sling converted at a one point sling. let it hang then picked it up and fired 3 bursts at 50 yards then back down to rest.

    Also did firing switching over to the weak shoulder. Totally slow on the shooting on my left shoulder. It was fun but getting target acquisition with my left eye was "different". But still fun to try something new.

    Will try again for the 200 yard mark next weekend.
  13. Rossignol

    Rossignol The Original Sheriff Staff Member Global Moderator Moderator Sponsor

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    Still sounds productive and fun!!!
  14. Water Monkey

    Water Monkey The man, the myth, the monkey Moderator Supporter

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    200 yard update!!

    So it's been hell at the range everytime I've went for the 200 yard line. So since I had off all week for Turkey Hunting I ventured over at yet again another day of no Turkey lol.

    So here are the prelim results:

    200 yards, S&W M&P 15 sport, 55 grain 5.56 NATO Privy Partizan ammo, M4 Rear Iron Sight.

    (Round 1) 40 shots using M4 Rear Iron at -4 on the RIBZ sighting method:

    [​IMG]


    Shooting high like I expected. Pulling to the left a little too as there was a little wind.


    (Round 2) 40 shots using M4 Rear Iron at -6 on the RIBZ sighting Method:

    [​IMG]

    Trajectory flattened out quite a bit. I pulled to the right a little more than I should to compensate for wind. I just didnt feel like messing with windage on my sight for some reason. Being lazy I guess.

    Anyway I'm really shocked at the data so far. Yes I need a few more trips to the range to make a better conclusion.

    -4 hit high like expected. I also needed to aim a bit lower anyway. Because I couldnt see the red dot at 200 yards I bet I was aiming 2 inches above it right off the bat.

    -6 was more flatter than anticipated and I figured it would be much lower than it actually hit at 200 yards. Even with me aiming a bit lower to begin with.

    That's the data for now. May have more either this week or next week. Depends on when I can hit the range again. I'm thinking of doing 50 yards in 2 days. I wanna tape a quarter to the bullseye and rock it!

    Here was 50 yards 2 weeks ago using the same ammo:


    [​IMG]
  15. Rossignol

    Rossignol The Original Sheriff Staff Member Global Moderator Moderator Sponsor

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    Dang man, lookin pretty good as far as I'm concerned!

    Pretty cool you takin time to try out this system and come back with pics and results, thanks man!

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