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Posted: 3/13/2012 5:34:20 PM EDT
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I was recently issued a M68 CCO / Aimpoint CompM4s. At the zero range, the instructors from the training division told us to aim center-mass, but adjust for a grouping in the low part of the 25m zero silhouette. The theory was this was supposed to result in a center-mass hit at 300m.
I did this and was placing dime-sized groups at 25 meters, but at first, couldn't hit shit at 300 meters. We had 10 rounds for familiarization, so I used them all to determine windage. I found I had to put the dot on the bottom the target to hit it. If the target is 40" tall, that means aiming center mass, I'm hitting at least two feet high. With two exceptions, I've always shot Expert with iron sites, so the ballistics are baffling me. I would think that center-mass at 25m equals center-mass at 300m. I received permission from my commander to bring my optic home and I'm going to a 300 yard range tomorrow to practice. Any advice on zeroing? Is the CCO playing some kind of optical trick that makes zeroing different from iron sites? Thanks |
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Quoted:
I was recently issued a M68 CCO / Aimpoint CompM4s. At the zero range, the instructors from the training division told us to aim center-mass, but adjust for a grouping in the low part of the 25m zero silhouette. The theory was this was supposed to result in a center-mass hit at 300m. I did this and was placing dime-sized groups at 25 meters, but at first, couldn't hit shit at 300 meters. We had 10 rounds for familiarization, so I used them all to determine windage. I found I had to put the dot on the bottom the target to hit it. If the target is 40" tall, that means aiming center mass, I'm hitting at least two feet high. With two exceptions, I've always shot Expert with iron sites, so the ballistics are baffling me. I would think that center-mass at 25m equals center-mass at 300m. I received permission from my commander to bring my optic home and I'm going to a 300 yard range tomorrow to practice. Any advice on zeroing? Is the CCO playing some kind of optical trick that makes zeroing different from iron sites? Thanks The Army AMU states that if your zeroing at 25 meters with a M4, ideally your impacts should be in the bottom half of the circle in the reduced silhouette. Not the bottom of the silhouette. So they want your impacts about 1/3 inch low at 25 meters. |
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Quoted:
Quoted:
I was recently issued a M68 CCO / Aimpoint CompM4s. At the zero range, the instructors from the training division told us to aim center-mass, but adjust for a grouping in the low part of the 25m zero silhouette. The theory was this was supposed to result in a center-mass hit at 300m. I did this and was placing dime-sized groups at 25 meters, but at first, couldn't hit shit at 300 meters. We had 10 rounds for familiarization, so I used them all to determine windage. I found I had to put the dot on the bottom the target to hit it. If the target is 40" tall, that means aiming center mass, I'm hitting at least two feet high. With two exceptions, I've always shot Expert with iron sites, so the ballistics are baffling me. I would think that center-mass at 25m equals center-mass at 300m. I received permission from my commander to bring my optic home and I'm going to a 300 yard range tomorrow to practice. Any advice on zeroing? Is the CCO playing some kind of optical trick that makes zeroing different from iron sites? Thanks The Army AMU states that if your zeroing at 25 meters with a M4, ideally your impacts should be in the bottom half of the circle in the reduced silhouette. Not the bottom of the silhouette. So they want your impacts about 1/3 inch low at 25 meters. I found this in the FM, which indicates I should want impact one square below POA. I wonder if it's because we zero at 3/8+1 and the CCO is not adjusted. This still doesn't explain why I can't hit 300m. I wonder if I had consistant parallax issues at 25m, which screwed up my 300m POI. 
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Choke the brightness of the dot as low as you can so glare isn't making it seem even larger. It's not a very fine aiming point for 300 Meters/328yards.
I believe it is 2MOA which is over 6 inches at 300 meters. I would sight in with irons then turn on the dot as dim as I could and set it so the top of the dot is level with the top of the post when using irons. That way with the light choked down to minimum you can use the top of the dot as an aiming point for 300 meters and bottom of the dot at 400. Remember you should always verify your zero at longer range. This will adjust for minor variances from small factors of applied physics as well as any difference in the actuall sight picture at longer distance that you may do without realizing it. Given 2.6 inch height above bore for irons and figuring absolute co-witness would be the same. Here is your trajectory for 300 meters if the load makes 3050fps in M16. About half inch low at 25 meters 27.5 yards. BC and Velocity are rough estimates. I'm on dial up damn it. 
Load Data Courtesy Point Blank software downloaded from RCBS I believe. In yards not meters. ~~~~~~~~~ Name: 855 Ballistic Coeff: 0.350 Bullet Weight: 62 Velocity: 3050 Target Distance: 328 yards Scope Height: 2.600 Temperature: 70 Altitude: 500 Ballistic Data ~~~~~~~~~~~~~~~ Range Elevation Velocity Energy ETA Drop Max Y 10mph Wind Deflect 0 yds -2.60 in 3050 fps 1281 fpe 0.000 sec 0.00 in -2.60 in 0.00 in 25 yds -0.63 in 2983 fps 1225 fpe 0.025 sec 0.12 in -1.01 in 0.05 in 50 yds 1.09 in 2917 fps 1171 fpe 0.050 sec 0.48 in -0.92 in 0.17 in 75 yds 2.56 in 2852 fps 1119 fpe 0.076 sec 1.09 in -0.76 in 0.41 in 100 yds 3.76 in 2788 fps 1070 fpe 0.103 sec 1.98 in -0.53 in 0.78 in 125 yds 4.68 in 2725 fps 1022 fpe 0.130 sec 3.15 in -0.22 in 1.26 in 150 yds 5.30 in 2662 fps 976 fpe 0.158 sec 4.61 in 0.17 in 1.85 in 175 yds 5.62 in 2601 fps 931 fpe 0.187 sec 6.37 in 0.65 in 2.54 in 200 yds 5.63 in 2540 fps 888 fpe 0.216 sec 8.45 in 1.22 in 3.33 in 225 yds 5.29 in 2480 fps 847 fpe 0.246 sec 10.87 in 1.89 in 4.26 in 250 yds 4.63 in 2421 fps 807 fpe 0.276 sec 13.62 in 2.66 in 5.27 in 275 yds 3.58 in 2363 fps 769 fpe 0.307 sec 16.76 in 3.55 in 6.45 in 300 yds 2.13 in 2306 fps 732 fpe 0.339 sec 20.30 in 4.56 in 7.80 in 325 yds 0.25 in 2249 fps 696 fpe 0.372 sec 24.25 in 5.70 in 9.29 in 350 yds -2.05 in 2193 fps 662 fpe 0.406 sec 28.65 in 6.99 in 10.94 in 375 yds -4.81 in 2138 fps 629 fpe 0.441 sec 33.48 in 8.42 in 12.72 in 400 yds -8.02 in 2084 fps 598 fpe 0.477 sec 38.78 in 10.00 in 14.64 in 425 yds -11.70 in 2031 fps 568 fpe 0.513 sec 44.54 in 11.75 in 16.70 in 450 yds -15.95 in 1978 fps 539 fpe 0.550 sec 50.88 in 13.68 in 18.97 in 475 yds -20.61 in 1925 fps 510 fpe 0.588 sec 57.63 in 15.77 in 21.28 in 500 yds -25.94 in 1874 fps 484 fpe 0.627 sec 65.05 in 18.09 in 23.87 in 525 yds -31.97 in 1824 fps 458 fpe 0.668 sec 73.16 in 20.65 in 26.70 in 550 yds -38.72 in 1775 fps 434 fpe 0.710 sec 81.99 in 23.47 in 29.76 in 575 yds -46.19 in 1728 fps 411 fpe 0.753 sec 91.55 in 26.54 in 33.05 in 600 yds -54.40 in 1681 fps 389 fpe 0.798 sec 101.84 in 29.89 in 36.53 in 625 yds -63.36 in 1635 fps 368 fpe 0.843 sec 112.89 in 33.52 in 40.21 in 650 yds -73.09 in 1590 fps 348 fpe 0.890 sec 124.70 in 37.44 in 44.07 in 675 yds -83.58 in 1546 fps 329 fpe 0.937 sec 137.28 in 41.65 in 48.10 in 700 yds -94.86 in 1502 fps 311 fpe 0.986 sec 150.64 in 46.18 in 52.30 in 725 yds -107.42 in 1461 fps 294 fpe 1.036 sec 165.29 in 51.16 in 56.90 in 750 yds -120.97 in 1421 fps 278 fpe 1.088 sec 180.93 in 56.53 in 61.72 in 775 yds -135.75 in 1383 fps 263 fpe 1.142 sec 197.80 in 62.36 in 66.85 in 800 yds -151.75 in 1346 fps 249 fpe 1.197 sec 215.87 in 68.64 in 72.25 in Moving Target Lead Data ~~~~~~~~~~~~~~~~~~~~~~~ Range 5 Mph 10 Mph 15 Mph 20 Mph 25 Mph 30 Mph 35 Mph 40 Mph 45 Mph 50 Mph 55 Mph 60 Mph 0 yds 0.00 ft 0.00 ft 0.00 ft 0.00 ft 0.00 ft 0.00 ft 0.00 ft 0.00 ft 0.00 ft 0.00 ft 0.00 ft 0.00 ft 25 yds 0.18 ft 0.36 ft 0.55 ft 0.73 ft 0.91 ft 1.09 ft 1.28 ft 1.46 ft 1.64 ft 1.82 ft 2.00 ft 2.19 ft 50 yds 0.37 ft 0.74 ft 1.10 ft 1.47 ft 1.84 ft 2.21 ft 2.57 ft 2.94 ft 3.31 ft 3.68 ft 4.04 ft 4.41 ft 75 yds 0.56 ft 1.12 ft 1.67 ft 2.23 ft 2.79 ft 3.35 ft 3.91 ft 4.47 ft 5.02 ft 5.58 ft 6.14 ft 6.70 ft 100 yds 0.75 ft 1.51 ft 2.26 ft 3.02 ft 3.77 ft 4.52 ft 5.28 ft 6.03 ft 6.78 ft 7.54 ft 8.29 ft 9.05 ft 125 yds 0.95 ft 1.91 ft 2.86 ft 3.82 ft 4.77 ft 5.72 ft 6.68 ft 7.63 ft 8.59 ft 9.54 ft 10.49 ft 11.45 ft 150 yds 1.16 ft 2.32 ft 3.48 ft 4.64 ft 5.79 ft 6.95 ft 8.11 ft 9.27 ft 10.43 ft 11.59 ft 12.75 ft 13.91 ft 175 yds 1.37 ft 2.74 ft 4.10 ft 5.47 ft 6.84 ft 8.21 ft 9.58 ft 10.94 ft 12.31 ft 13.68 ft 15.05 ft 16.42 ft 200 yds 1.58 ft 3.16 ft 4.74 ft 6.33 ft 7.91 ft 9.49 ft 11.07 ft 12.65 ft 14.23 ft 15.81 ft 17.39 ft 18.98 ft 225 yds 1.80 ft 3.60 ft 5.40 ft 7.20 ft 9.00 ft 10.80 ft 12.60 ft 14.40 ft 16.20 ft 18.00 ft 19.81 ft 21.61 ft 250 yds 2.02 ft 4.05 ft 6.07 ft 8.09 ft 10.11 ft 12.14 ft 14.16 ft 16.18 ft 18.21 ft 20.23 ft 22.25 ft 24.28 ft 275 yds 2.25 ft 4.51 ft 6.76 ft 9.01 ft 11.26 ft 13.52 ft 15.77 ft 18.02 ft 20.27 ft 22.53 ft 24.78 ft 27.03 ft 300 yds 2.49 ft 4.98 ft 7.47 ft 9.96 ft 12.44 ft 14.93 ft 17.42 ft 19.91 ft 22.40 ft 24.89 ft 27.38 ft 29.87 ft 325 yds 2.73 ft 5.46 ft 8.19 ft 10.93 ft 13.66 ft 16.39 ft 19.12 ft 21.85 ft 24.58 ft 27.31 ft 30.05 ft 32.78 ft 350 yds 2.98 ft 5.96 ft 8.94 ft 11.92 ft 14.90 ft 17.88 ft 20.86 ft 23.84 ft 26.82 ft 29.80 ft 32.78 ft 35.76 ft 375 yds 3.24 ft 6.47 ft 9.71 ft 12.94 ft 16.18 ft 19.41 ft 22.65 ft 25.88 ft 29.12 ft 32.35 ft 35.59 ft 38.82 ft 400 yds 3.50 ft 6.99 ft 10.49 ft 13.98 ft 17.48 ft 20.97 ft 24.47 ft 27.96 ft 31.46 ft 34.95 ft 38.45 ft 41.95 ft 425 yds 3.76 ft 7.52 ft 11.28 ft 15.05 ft 18.81 ft 22.57 ft 26.33 ft 30.09 ft 33.85 ft 37.61 ft 41.37 ft 45.14 ft 450 yds 4.04 ft 8.07 ft 12.11 ft 16.14 ft 20.18 ft 24.22 ft 28.25 ft 32.29 ft 36.33 ft 40.36 ft 44.40 ft 48.43 ft 475 yds 4.31 ft 8.63 ft 12.94 ft 17.25 ft 21.57 ft 25.88 ft 30.19 ft 34.50 ft 38.82 ft 43.13 ft 47.44 ft 51.76 ft 500 yds 4.60 ft 9.20 ft 13.80 ft 18.40 ft 23.00 ft 27.61 ft 32.21 ft 36.81 ft 41.41 ft 46.01 ft 50.61 ft 55.21 ft 525 yds 4.90 ft 9.80 ft 14.70 ft 19.60 ft 24.50 ft 29.40 ft 34.30 ft 39.19 ft 44.09 ft 48.99 ft 53.89 ft 58.79 ft 550 yds 5.21 ft 10.41 ft 15.62 ft 20.83 ft 26.04 ft 31.24 ft 36.45 ft 41.66 ft 46.87 ft 52.07 ft 57.28 ft 62.49 ft 575 yds 5.52 ft 11.05 ft 16.57 ft 22.10 ft 27.62 ft 33.15 ft 38.67 ft 44.20 ft 49.72 ft 55.25 ft 60.77 ft 66.29 ft 600 yds 5.85 ft 11.70 ft 17.55 ft 23.40 ft 29.25 ft 35.10 ft 40.95 ft 46.80 ft 52.65 ft 58.50 ft 64.35 ft 70.20 ft 625 yds 6.18 ft 12.37 ft 18.55 ft 24.73 ft 30.92 ft 37.10 ft 43.29 ft 49.47 ft 55.65 ft 61.84 ft 68.02 ft 74.21 ft 650 yds 6.52 ft 13.05 ft 19.57 ft 26.10 ft 32.62 ft 39.15 ft 45.67 ft 52.20 ft 58.72 ft 65.25 ft 71.77 ft 78.30 ft 675 yds 6.87 ft 13.75 ft 20.62 ft 27.49 ft 34.37 ft 41.24 ft 48.11 ft 54.99 ft 61.86 ft 68.73 ft 75.61 ft 82.48 ft 700 yds 7.23 ft 14.46 ft 21.68 ft 28.91 ft 36.14 ft 43.37 ft 50.60 ft 57.83 ft 65.05 ft 72.28 ft 79.51 ft 86.74 ft 725 yds 7.60 ft 15.20 ft 22.80 ft 30.40 ft 38.00 ft 45.60 ft 53.20 ft 60.80 ft 68.40 ft 76.00 ft 83.60 ft 91.20 ft 750 yds 7.98 ft 15.96 ft 23.94 ft 31.93 ft 39.91 ft 47.89 ft 55.87 ft 63.85 ft 71.83 ft 79.82 ft 87.80 ft 95.78 ft 775 yds 8.38 ft 16.75 ft 25.13 ft 33.50 ft 41.88 ft 50.25 ft 58.63 ft 67.01 ft 75.38 ft 83.76 ft 92.13 ft 100.51 ft 800 yds 8.78 ft 17.56 ft 26.34 ft 35.12 ft 43.91 ft 52.69 ft 61.47 ft 70.25 ft 79.03 ft 87.81 ft 96.59 ft 105.37 ft |
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I was recently issued a M68 CCO / Aimpoint CompM4s. At the zero range, the instructors from the training division told us to aim center-mass, but adjust for a grouping in the low part of the 25m zero silhouette. The theory was this was supposed to result in a center-mass hit at 300m. I did this and was placing dime-sized groups at 25 meters, but at first, couldn't hit shit at 300 meters. We had 10 rounds for familiarization, so I used them all to determine windage. I found I had to put the dot on the bottom the target to hit it. If the target is 40" tall, that means aiming center mass, I'm hitting at least two feet high. With two exceptions, I've always shot Expert with iron sites, so the ballistics are baffling me. I would think that center-mass at 25m equals center-mass at 300m. I received permission from my commander to bring my optic home and I'm going to a 300 yard range tomorrow to practice. Any advice on zeroing? Is the CCO playing some kind of optical trick that makes zeroing different from iron sites? Thanks The Army AMU states that if your zeroing at 25 meters with a M4, ideally your impacts should be in the bottom half of the circle in the reduced silhouette. Not the bottom of the silhouette. So they want your impacts about 1/3 inch low at 25 meters. I found this in the FM, which indicates I should want impact one square below POA. I wonder if it's because we zero at 3/8+1 and the CCO is not adjusted. This still doesn't explain why I can't hit 300m. I wonder if I had consistant parallax issues at 25m, which screwed up my 300m POI. http://i4.photobucket.com/albums/y126/von_landstuhl/AR15/1331697837.png That's a pretty good start. Set the irons to actual 300 after sight in. Then creep the dot up a little at a time so top of dot equals top of post. Like I said there are minor factors that mean you need to check actual performance of the setting at long range. Some of these can be accounted for by physics. Some by variance in your site picture between scaled target and actual distance. Back in the 80’s a guy tested 10 expert marksmen using only the 25 meter sight in. Then 25 meter with verification at longer ranges with adjustments made. 80 percent missed targets first time around and all shot 100 percent after sighting in at actual distance of 300 meters. |
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Thanks for the data.
Remember you should always verify your zero at longer range. This will adjust for minor variances from small factors of applied physics as well as any difference in the actuall sight picture at longer distance that you may do without realizing it.
I agree 100%, but unfortunately, the Army Reserve trains to time, not to standard. When the focus is on meeting the minimum qualification score (ie, go vs no go, rather than marksman vs expert), verifying zero on a KD range isn't even considered. You wouldn't believe the grief I got when I asked to bring my CCO home. Thankfully, my chain of command was more helpful than the NCO support channel. |
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A few months ago there was a great magazine article on how to improve your shooting using what you were actually to be issued/allowed per range trip.
Instead of sighting in and running off to the range you use more targets and one shot per target for individual feedback for each shot made. |
| If you use the target above and get a nice solid zero at 25m, you will be fine at 300. Like the other poster said, turn your brightness down as low as you can go and see it. A grippod helps as well. Your supply should have then as well if you are using the M4. Part of the normal package. |
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I'm back. I zeroed the CCO at 25m to 1" groups, then moved to 300 yards. I was using the back of an Alternate Course C target (roughly 18x24) with a stick-on Shoot-N-C 12" bullseye. Right off the bat, I was hitting paper in 6" groups. They were a little low and to the right, so I adjusted for zero. When I dialed it in, I went back to 25m and found I was hitting center-mass there, too.
Not sure why the FM calls for zeroing low, but in the end, I seemed to not need it. Also, since I didn't miss paper today, I'm not sure why I missed 300m with the pre-qualification familiarization rounds. While I accomplished what I wanted to do today, it was so effortless, it almost seemed like a waste of a day. My 3-round 25m zero (the diamond is a one-inch square): 
My second 10-round group at 300y: 
My last 5-round group at 25m (yes, I shanked one): 
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I'm back. I zeroed the CCO at 25m to 1" groups, then moved to 300 yards. I was using the back of an Alternate Course C target (roughly 18x24) with a stick-on Shoot-N-C 12" bullseye. Right off the bat, I was hitting paper in 6" groups. They were a little low and to the right, so I adjusted for zero. When I dialed it in, I went back to 25m and found I was hitting center-mass there, too. Not sure why the FM calls for zeroing low, but in the end, I seemed to not need it. Also, since I didn't miss paper today, I'm not sure why I missed 300m with the pre-qualification familiarization rounds. While I accomplished what I wanted to do today, it was so effortless, it almost seemed like a waste of a day. My 3-round 25m zero (the diamond is a one-inch square): http://i4.photobucket.com/albums/y126/von_landstuhl/AR15/1331767914.jpg My second 10-round group at 300y: http://i4.photobucket.com/albums/y126/von_landstuhl/AR15/1331768057.jpg My last 5-round group at 25m (yes, I shanked one): http://i4.photobucket.com/albums/y126/von_landstuhl/AR15/1331768183.jpg You are more likely to get a variation in your sight picture using the mil standard sight in target and full size silouhette at 300 vs using standard civilian targets. You should practice with what you will shoot for record if you want good score. Now for realistic training shoot at a picture of a terrorist at 300 yards. You knew there was a use for those old Che posters left behind by the Obama campaigners didn't you? There are some pics of Osama you could blow up to life size. 
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