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Posted: 11/5/2012 11:55:31 AM EDT
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I have an SLR 95 that I zeroed at 25 meters with the rear sight on "2" (200 meters). After that I put the rear sight on "1" and the rifle is dead on at 100 meters. This validates the trajectory I calculated on two different ballistic calculators wherein the 25 meter zero crosses over at 200.
I often see folks recommending putting the rear sight on "1" to zero at 25 meters. But experience with my rifle and two calculators tells me different. Using a BC of .29, velocity 2400 fps, sight height over bore of 1.8", I get a crossover at 25 meters/200 meters. What am I missing, or do I just call it good? |
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confirm on 200 meter range, then call it good. I like it. If it confirms at 200 meters, I'm done. I zero at 25m on the battle zero of the rear site and verify at 100m.
Are you saying that you set the sight at "1' and it's the same POA/POI at both 25 and 100? This doesn't work on my SLR95. I often read this, but when I look at the crossover for 25 meters, it's much closer to 200 than 300 meters, but never 100 meters, again, unless I'm missing something. |
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I have an SLR 95 that I zeroed at 25 meters with the rear sight on "2" (200 meters). After that I put the rear sight on "1" and the rifle is dead on at 100 meters. This validates the trajectory I calculated on two different ballistic calculators wherein the 25 meter zero crosses over at 200. I often see folks recommending putting the rear sight on "1" to zero at 25 meters. But experience with my rifle and two calculators tells me different. Using a BC of .29, velocity 2400 fps, sight height over bore of 1.8", I get a crossover at 25 meters/200 meters. What am I missing, or do I just call it good? thats the zero i use! |
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The winchester ballistics app on my phone is telling me that your setup will hit at 25 and 180 with their ammo (Q3174... BC of .245 and muzzle velocity of 2355).
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confirm on 200 meter range, then call it good. I like it. If it confirms at 200 meters, I'm done. I zero at 25m on the battle zero of the rear site and verify at 100m.
Are you saying that you set the sight at "1' and it's the same POA/POI at both 25 and 100? This doesn't work on my SLR95. I often read this, but when I look at the crossover for 25 meters, it's much closer to 200 than 300 meters, but never 100 meters, again, unless I'm missing something. The battlesight setting is the position before the 1. It is about the same as the 3 setting. I think he is just saying he sets it on that position, then zeros it at 100. |
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The battlesight setting is the position before the 1. It is about the same as the 3 setting.
I think he is just saying he sets it on that position, then zeros it at 100. That's what I thought, too. I understand BZ=300. The winchester ballistics app on my phone is telling me that your setup will hit at 25 and 180 with their ammo (Q3174... BC of .245 and muzzle velocity of 2355).
Cool. Was that yards or meters? I actually zeroed at 25 meters, but checked it a 100 yards. (That was the farthest distance available) FYI, I was using Wolf 124 gr HP. The gun seems to like it. I have shot it right at 1 MOA, but typically 1.5 to 2 MOA if I'm bagged in and having a good day. |
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Quoted:
The winchester ballistics app on my phone is telling me that your setup will hit at 25 and 180 with their ammo (Q3174... BC of .245 and muzzle velocity of 2355). Quoted:
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confirm on 200 meter range, then call it good. I like it. If it confirms at 200 meters, I'm done. I zero at 25m on the battle zero of the rear site and verify at 100m.
Are you saying that you set the sight at "1' and it's the same POA/POI at both 25 and 100? This doesn't work on my SLR95. I often read this, but when I look at the crossover for 25 meters, it's much closer to 200 than 300 meters, but never 100 meters, again, unless I'm missing something. The battlesight setting is the position before the 1. It is about the same as the 3 setting. I think he is just saying he sets it on that position, then zeros it at 100. how is the right way? zero with 1 at 100m then battle zero to go from 100 to 200-300? I have never used the battle zero but I'm up to learning new stuff. |
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Quoted:
The battlesight setting is the position before the 1. It is about the same as the 3 setting.
I think he is just saying he sets it on that position, then zeros it at 100. That's what I thought, too. I understand BZ=300. The winchester ballistics app on my phone is telling me that your setup will hit at 25 and 180 with their ammo (Q3174... BC of .245 and muzzle velocity of 2355).
Cool. Was that yards or meters? I actually zeroed at 25 meters, but checked it a 100 yards. (That was the farthest distance available) FYI, I was using Wolf 124 gr HP. The gun seems to like it. I have shot it right at 1 MOA, but typically 1.5 to 2 MOA if I'm bagged in and having a good day. The app uses yards. |
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On this calculator, using a BC of .26, muzzle velocity of 2330, and a sight height of 2" ( I just measured) ,a 25 YARD zero gets a crossover of 200, but a 25 METER zero crosses closer to 180. I keep it the rear sight on "2" for this, then move it to "1" to check at 100'.
Or, zero at 100 on setting "1", and then check at 25/200 on setting "2". |
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I found this while back and liked it.
Zeroing an AK47 the following is taken from G&A's Complete Book of the AK47 (2009) article titled Zeroing the AK47 by James Tarr (pgs 86-87) Official Soviet Procedure: 1.Place a confirmation target at 100m (109.4y) with a spot or edge you can aim at precisely. Control point or required point of impact shall be 25cm (approx 10") above point of aim. 2.Set rear sight at 300m 3.From prone position with firearm supported on sandbag fire 4 aimed shots at center of bottom edge of black portion of confirmation target 4.Group shall be no larger than 15cm (5.9"). One flier permitted 5.Center group shall be no farther than 5cm (1.97") from control point. If not adjust sights and repeat until 6.Set rear sight at 100m. Rifle is now zeroed Note: Specific target for zeroing in this manner issued by the Soviets consists of a black rectangle 35cm high by 25cm wide (14x10") centered in a white background 1m high by .5m wide (39.3x19.6"). Aiming point is middle of black rectangle lower edge New Method 1.Set rear sight to 100m and place sight in target at 25m (82') 2.Sight in so so bullets are hitting exactly point of aim. Rifle is sighted for any range 3.After, if set sight on Battle Sight setting (lowest on scale), you can hit man-size target any range from 0 to 400m without changing the sight setting Note: Best reserved for when only a 25m range is available |
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I found this while back and liked it. Zeroing an AK47 the following is taken from G&A's Complete Book of the AK47 (2009) article titled Zeroing the AK47 by James Tarr (pgs 86-87) Official Soviet Procedure: 1.Place a confirmation target at 100m (109.4y) with a spot or edge you can aim at precisely. Control point or required point of impact shall be 25cm (approx 10") above point of aim. 2.Set rear sight at 300m 3.From prone position with firearm supported on sandbag fire 4 aimed shots at center of bottom edge of black portion of confirmation target 4.Group shall be no larger than 15cm (5.9"). One flier permitted 5.Center group shall be no farther than 5cm (1.97") from control point. If not adjust sights and repeat until 6.Set rear sight at 100m. Rifle is now zeroed Note: Specific target for zeroing in this manner issued by the Soviets consists of a black rectangle 35cm high by 25cm wide (14x10") centered in a white background 1m high by .5m wide (39.3x19.6"). Aiming point is middle of black rectangle lower edge New Method 1.Set rear sight to 100m and place sight in target at 25m (82') 2.Sight in so so bullets are hitting exactly point of aim. Rifle is sighted for any range 3.After, if set sight on Battle Sight setting (lowest on scale), you can hit man-size target any range from 0 to 400m without changing the sight setting Note: Best reserved for when only a 25m range is available I'm liking method-2 the "new method" myself. KISS simple. |
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I found this while back and liked it. Zeroing an AK47 the following is taken from G&A's Complete Book of the AK47 (2009) article titled Zeroing the AK47 by James Tarr (pgs 86-87) Official Soviet Procedure: 1.Place a confirmation target at 100m (109.4y) with a spot or edge you can aim at precisely. Control point or required point of impact shall be 25cm (approx 10") above point of aim. 2.Set rear sight at 300m 3.From prone position with firearm supported on sandbag fire 4 aimed shots at center of bottom edge of black portion of confirmation target 4.Group shall be no larger than 15cm (5.9"). One flier permitted 5.Center group shall be no farther than 5cm (1.97") from control point. If not adjust sights and repeat until 6.Set rear sight at 100m. Rifle is now zeroed Note: Specific target for zeroing in this manner issued by the Soviets consists of a black rectangle 35cm high by 25cm wide (14x10") centered in a white background 1m high by .5m wide (39.3x19.6"). Aiming point is middle of black rectangle lower edge It should be mentioned that with this procedure, soviet troops were trained to aim for their targets belt buckle. That is why a 10" high POI at 100m is fine.. it'll hit the target in the chest when the troops aim at the belt buckle. It isn't going to work so well with the American way of aiming center mass.. you'll either get a headshot or just miss at 100 with this zero. |
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Quoted:
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I found this while back and liked it. Zeroing an AK47 the following is taken from G&A's Complete Book of the AK47 (2009) article titled Zeroing the AK47 by James Tarr (pgs 86-87) Official Soviet Procedure: 1.Place a confirmation target at 100m (109.4y) with a spot or edge you can aim at precisely. Control point or required point of impact shall be 25cm (approx 10") above point of aim. 2.Set rear sight at 300m 3.From prone position with firearm supported on sandbag fire 4 aimed shots at center of bottom edge of black portion of confirmation target 4.Group shall be no larger than 15cm (5.9"). One flier permitted 5.Center group shall be no farther than 5cm (1.97") from control point. If not adjust sights and repeat until 6.Set rear sight at 100m. Rifle is now zeroed Note: Specific target for zeroing in this manner issued by the Soviets consists of a black rectangle 35cm high by 25cm wide (14x10") centered in a white background 1m high by .5m wide (39.3x19.6"). Aiming point is middle of black rectangle lower edge New Method 1.Set rear sight to 100m and place sight in target at 25m (82') 2.Sight in so so bullets are hitting exactly point of aim. Rifle is sighted for any range 3.After, if set sight on Battle Sight setting (lowest on scale), you can hit man-size target any range from 0 to 400m without changing the sight setting Note: Best reserved for when only a 25m range is available I'm liking method-2 the "new method" myself. KISS simple. +1! 
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| I zero at 50 yds with rear sight on '1', then confirm at 100 yds, maybe making some slight adjustments. Starting on 50 yds saves ammo and a lot of chasing the sights at 100. Similar to the 'New Method' above. Either way, if you are hitting the bulls eye at 100 with the rear sight on '1', the sight is then indexed for all range positions, at least in the battle-sight sense. Realistically, with the AK iron sights, this is close enough. In a real combat scenario, you would most likely set the rear sight on the battlesight setting and use the 6:00 hold to get torso hits out to 300. I can't see anybody trying to shoot an AK farther than that with the irons, but obviously it does happen from time to time. |
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Great thread.
Just a note. The various miIitary zero settings are fine for known range shooting of paper targets, etc, but have a severe downside for practical field use. A 10" high zero {100m} makes for a very difficult hold on common varmints like coyotes, or deer if that is on the agenda at ranges where such game is most commonly shot {quite a bit less than 300m}. Such a zero makes the lion's share of field shooting more difficult in exchange for a zero of dubious value based on the limitations of the equipment. 10" high zero means extreme round POI might be over a foot high and still be within acceptable grouping for the rifle. Remember, accuracy past 100m degrades pretty fast with a 7.62x39 AK, soooo.... A zero of dead-on to 3 inches MAX high at 100m is not actually a disadvantage {tho it may be implied as such by the common military zero's} for shooting of varmints or game. Regardless of whether the gun is zeroed "for 300m" actual ability to hit a coyote, for example, at 300 is very, very, difficult, edging into the realm of a "lucky shot". This is demonstrated by the group standard mentioned in the Soviet material {4 shots/5.9" + flyer} which represents honest performance for many AK's. Thus,for field shooting, a guy is better to keep his midrange trajectory no higher than 3 or at extreme 4 inches high, giving a zero of less than 300m admittedly, but of far more general utility in the field. |
| That is exactly why we zero at 100 at the '1' setting. 'Zero' means that the point of impact equals the point of aim. This is a very useful trajectory out to about 150. For true combat shooting, which is highly unlikely for any of us, the battlesight setting is probably best because of targets appearing at any and all ranges. |
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For true combat shooting, which is highly unlikely for any of us, the battlesight setting is probably best because of targets appearing at any and all ranges. My take is simply this; I'd sure think that for a rifle that possesses the limited accuracy potential of the 7.62 AK, the zero, even for a combat arm, should nevertheless be kept to a midrange less than 6 inches, preferably less than 4. Problem is, group radius needs to be added to midrange height for a true "possible". That accuracy potential eliminates helmet sized groups at much past 100 meters if ANY misjudgement of range occurs, which is common enough in fast shooting. So I'd say your "on" at 100m or up to 2 inches high is still far preferable to a hold that requires hold-under at less than zero range. This is all based on my experience on game and varmints, of which I've shot a lot. Your "on" or 1" high would give you a good useful and quickly applied zero for a "point blank" out to 200 yards on, beyond which the accuracy potential of the rifle is wholly unreliable on any enemy lying prone and sketchy even on an enemy combatant standing at "Attention". Remember the rudimentary sights and, well, you get the picture. I'd want the combat arm sighted just as you sight the rifle for your shooting. This is actually true of the 5.56 round, too, which requires a roughly 6" high POI at 100m for 55 or 62 grain ammo and a 300m zero. A guy can hold dead on a coyote's shoulder and miss it at 110 meters using that zero and unless I am doing 300m work specifically I do not want the gun zeroed at 300. I always kept my AK's zeroed as you do, by the way. Incidentally, this was all figured out during WW1 when going into it many service weapons had minimum elevation that left the rifles still very high at 100m. In trench combat, troop complaints were generated due to poor sighting of rifles for the most commonly encountered need. After the war, most updated rifle sights were equipped to provide zero potential at 100. And this with rifles that are far flatter shooting than the 7.62x39. |
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New Method
1.Set rear sight to 100m and place sight in target at 25m (82') 2.Sight in so so bullets are hitting exactly point of aim. Rifle is sighted for any range 3.After, if set sight on Battle Sight setting (lowest on scale), you can hit man-size target any range from 0 to 400m without changing the sight setting Note: Best reserved for when only a 25m range is available It sounds good, but in my (admittedly limited) experience, the POI at 25 and 100 with the RS set to "1", is NOT the same. It isn't the same in practice OR on any ballistic calculator that I have used. I take comfort when my roughly 2 inch groups at 100 are centered at the POA on setting"1". I am going to take the suggestion to check at 200 on "2", though. Maybe even fine tune at 200 and then just figure out what the exact crossover is in close. By the way, isn't 200 zero a more useful trajectory for an urban setting? Its never more than 5 inches or so high or low all the way to about 250. It's way flatter than the 300 trajectory, which crosses at about 18' and goes as much as 10" high at 170. In the situation where I KNOW I'm at at 300+, I could just move the sight to "3", etc. or hold over a bit. Great comments, folks. |
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New Method
1.Set rear sight to 100m and place sight in target at 25m (82') 2.Sight in so so bullets are hitting exactly point of aim. Rifle is sighted for any range 3.After, if set sight on Battle Sight setting (lowest on scale), you can hit man-size target any range from 0 to 400m without changing the sight setting Note: Best reserved for when only a 25m range is available It sounds good, but in my (admittedly limited) experience, the POI at 25 and 100 with the RS set to "1", is NOT the same. It isn't the same in practice OR on any ballistic calculator that I have used. I take comfort when my roughly 2 inch groups at 100 are centered at the POA on setting"1". I am going to take the suggestion to check at 200 on "2", though. Maybe even fine tune at 200 and then just figure out what the exact crossover is in close. By the way, isn't 200 zero a more useful trajectory for an urban setting? Its never more than 5 inches or so high or low all the way to about 250. It's way flatter than the 300 trajectory, which crosses at about 18' and goes as much as 10" high at 170. In the situation where I KNOW I'm at at 300+, I could just move the sight to "3", etc. or hold over a bit. Great comments, folks. IMO, yes. I have found a 50m BZO to be the flattest trajectory period if staying under 300 yds. But most AK folks set their's as mentioned above if using irons. |
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IMO, yes. I have found a 50m BZO to be the flattest trajectory period if staying under 300 yds But with 7.62X39, (2" sight over bore, 2350 fps, and a BC of .265) there is no crossover at all with a 50 zero. It pretty much just drops starting at around 120, and by 240, it's more than 10" low.
Using the same data, a 200 yrd zero crosses at 25 yrds, peaks at 3.04 inches at 100 yds, and drops to -5.37 at 250 yards. That's the flattest zero I have been able to come up with at short to intermediate ranges. |
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