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Posted: 9/13/2014 12:02:25 PM EDT
| I need to sight in my wife's upper and planned on using this target. However, the shortest range I have access to is 50 yards. Is one click going to be closer to two boxes on this target? |
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A 25 meter zeroing target uses a 4 cm (1.574") circle to represent what an average male (48 cm from shoulder to shoulder) would look 300 meters away from your perspective when the zeroing target is placed 25 meters away. Using the principles of MOA, for the 4 cm circle to remain proportional as it is moved away from you; at 50 meters the circle would be 8 cm (3.149"). Converting to yards, at 50 yards use a circle that is 7.313 cm (2.879"); so 2.9" will work.
First, adjust windage and elevation to hit center mass, once done adjust only the elevation to hit 0.01 above center mass for a 20" barrel with a 19.8" sight radius, and to hit 0.43" above center mass for a 14.5" barrel with a 14.5" sight radius. As for the amount of change per click, that would be dependent on barrel length and sight radius, and also whether you are referring to windage, or the elevation for front sight post or carry handle. |
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Quoted:
A 25 meter zeroing target uses a 4 cm (1.574") circle to represent what an average male (48 cm from shoulder to shoulder) would look 300 meters away from your perspective when the zeroing target is placed 25 meters away. Using the principles of MOA, for the 4 cm circle to remain proportional as it is moved away from you; at 50 meters the circle would be 8 cm (3.149"). Converting to yards, at 50 yards use a circle that is 7.313 cm (2.879"); so 2.9" will work. First, adjust windage and elevation to hit center mass, once done adjust only the elevation to hit 0.01 above center mass for a 20" barrel with a 19.8" sight radius, and to hit 0.43" above center mass for a 14.5" barrel with a 14.5" sight radius. As for the amount of change per click, that would be dependent on barrel length and sight radius, and also whether you are referring to windage, or the elevation for front sight post or carry handle. This is really great information thank you. The rifle in question is a 16" barrel with a F marked FSB and a colt carry handle. |
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Quoted: Larry Vickers advises against a 25 meter where POI is the same as POA. That the POI should be a few inches below POA at 25m. Because it'll throw off your shooting at different ranges, and that it makes the rifle basically a submachine gun.
Correct. Because...."the flight path of a [M855] bullet fired from an M16A2/A4 rifle with a true 300M zero. Current Army doctrine states that we must acquire a point of aim point of impact zero at 25M to achieve a point of aim point of impact zero at 300M where the bullet crosses the line of sight again. Note that the bullet impacts .33 inches low at 25M. This is why it is necessary to raise the BDC to 8/3 plus one click during the zeroing process, and then return the BDC to 8/3 for qualification or battle." With that said...."the flight path of a [M855] bullet fired from an M4 rifle with a true 300M zero. Note that the bullet impacts .03 inches low at 25M. This amount is negligible, and also why it is not necessary to raise the BDC up one click as it is done on the A2 or A4. The M4 is kept at 6/3 both for zeroing and battle." This information was taken from a presentation by the US Army Marksmanship Unit |
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Quoted:
Just a thought. Larry Vickers advises against a 25 meter where POI is the same as POA. That the POI should be a few inches below POA at 25m. Because it'll throw off your shooting at different ranges, and that it makes the rifle basically a submachine gun. I don't follow. can you post his comments on this. I'm nat a fan of a 25 yard zero but regardless of what range you choose to zero your weapon at you will have to know or figure out your POA/POI at different ranges and zeroing at 25, 36, 50 or 100(common zeroes) has no impact on the terminal ballistics of your ammo i.e. a 25 yard zero will not turn a 5.56(rifle) cartridge into a pistol(submachine gun) cartridge. |
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Quoted: I don't follow. can you post his comments on this. I'm nat a fan of a 25 yard zero but regardless of what range you choose to zero your weapon at you will have to know or figure out your POA/POI at different ranges and zeroing at 25, 36, 50 or 100(common zeroes) has no impact on the terminal ballistics of your ammo i.e. a 25 yard zero will not turn a 5.56(rifle) cartridge into a pistol(submachine gun) cartridge. Quoted: Quoted: Just a thought. Larry Vickers advises against a 25 meter where POI is the same as POA. That the POI should be a few inches below POA at 25m. Because it'll throw off your shooting at different ranges, and that it makes the rifle basically a submachine gun. I don't follow. can you post his comments on this. I'm nat a fan of a 25 yard zero but regardless of what range you choose to zero your weapon at you will have to know or figure out your POA/POI at different ranges and zeroing at 25, 36, 50 or 100(common zeroes) has no impact on the terminal ballistics of your ammo i.e. a 25 yard zero will not turn a 5.56(rifle) cartridge into a pistol(submachine gun) cartridge. See the post above yours And pretty much the best shooters in the world, the AMU. Have a thing about why you shouldnt either.
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Quoted:
See the post above yours And pretty much the best shooters in the world, the AMU. Have a thing about why you shouldnt either. Quoted:
Quoted:
Quoted:
Just a thought. Larry Vickers advises against a 25 meter where POI is the same as POA. That the POI should be a few inches below POA at 25m. Because it'll throw off your shooting at different ranges, and that it makes the rifle basically a submachine gun. I don't follow. can you post his comments on this. I'm nat a fan of a 25 yard zero but regardless of what range you choose to zero your weapon at you will have to know or figure out your POA/POI at different ranges and zeroing at 25, 36, 50 or 100(common zeroes) has no impact on the terminal ballistics of your ammo i.e. a 25 yard zero will not turn a 5.56(rifle) cartridge into a pistol(submachine gun) cartridge. See the post above yours And pretty much the best shooters in the world, the AMU. Have a thing about why you shouldnt either. Saw it and I read it. I still see know explanation as to how or why it will effect the terminal ballistics(turn a rifle into a sub gun) or did I misunderstand your post regarding his comment? or are those your comments regarding a subgun? I'm an advocate of the 50 yard zero and wouldn't use a 25 yard zero if you asked really, really nicely. |
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Quoted:
Correct. Because...."the flight path of a [M855] bullet fired from an M16A2/A4 rifle with a true 300M zero. Current Army doctrine states that we must acquire a point of aim point of impact zero at 25M to achieve a point of aim point of impact zero at 300M where the bullet crosses the line of sight again. Note that the bullet impacts .33 inches low at 25M. This is why it is necessary to raise the BDC to 8/3 plus one click during the zeroing process, and then return the BDC to 8/3 for qualification or battle." With that said...."the flight path of a [M855] bullet fired from an M4 rifle with a true 300M zero. Note that the bullet impacts .03 inches low at 25M. This amount is negligible, and also why it is not necessary to raise the BDC up one click as it is done on the A2 or A4. The M4 is kept at 6/3 both for zeroing and battle." This information was taken from a presentation by the US Army Marksmanship Unit Quoted:
Quoted: Larry Vickers advises against a 25 meter where POI is the same as POA. That the POI should be a few inches below POA at 25m. Because it'll throw off your shooting at different ranges, and that it makes the rifle basically a submachine gun.
Correct. Because...."the flight path of a [M855] bullet fired from an M16A2/A4 rifle with a true 300M zero. Current Army doctrine states that we must acquire a point of aim point of impact zero at 25M to achieve a point of aim point of impact zero at 300M where the bullet crosses the line of sight again. Note that the bullet impacts .33 inches low at 25M. This is why it is necessary to raise the BDC to 8/3 plus one click during the zeroing process, and then return the BDC to 8/3 for qualification or battle." With that said...."the flight path of a [M855] bullet fired from an M4 rifle with a true 300M zero. Note that the bullet impacts .03 inches low at 25M. This amount is negligible, and also why it is not necessary to raise the BDC up one click as it is done on the A2 or A4. The M4 is kept at 6/3 both for zeroing and battle." This information was taken from a presentation by the US Army Marksmanship Unit What the current thinking on the previously used USMC 25 meter zero(detailed in the older TM-10) where the rear sight elevation drum is reset to adjust 8/3 -3 clicks on the A2 and 6/3 -4 clicks with A4/detachable carry handle? |
In a class a few months ago, Larry was advocating zeroing about 2" low at 25 yards to achieve roughly a 100 yard zero. He said that they are basically 200 yard guns (at least with red dot optics), and he preferred the 100 yard zero to require less compensation to be precise in that sub 200 yard zone. Something about Delta Force and being set up well to go for head shots. 
He had the class zero low at 25 and then took them out to 100 to confirm. |
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