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Where does Rifle cant begin to matter?
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<blockquote data-quote="Hugnot" data-source="post: 2623797" data-attributes="member: 115658"><p>More info:</p><p></p><p>From Accurate Shooter...</p><p></p><p>[URL unfurl="true"]https://www.accurateshooter.com/optics/canting-effect-on-point-of-impact/[/URL]</p><p></p><p>My estimator:</p><p></p><p>A quicky estimator is to multiply the height of trajectory above line of sight by the sine of cant to give offset. Like for a .22-.250 75 ELD, MV 3150 at 600 yards sighted in at that range would have a mid-range trajectory of about 24 inches at 320-330 yards. Then 24 * .052(sin 3 degrees) = 1.24 inches offset. For 5 degrees the offset for same range & ammo would be .087 (sin 5 deg) * 24 = 2.088 inches.</p><p></p><p>For a .308 W shooting a 168 hpbt at 2550 fps with a 600 zero, the mid-range trajectory would be 38 inches and the 3-degree cant offset would be .052 (sin 3 deg) * 38 = 1.976 ~ 2 inches, enough to miss an X. Speed makes for flatter trajectories.</p><p></p><p>For a 300 WM with a 200 ELDX at 2800 fps at 1000 yards the mid-range trajectory would be 107 inches or just under 9 feet. The offset for a 3-degree cant would be 107 * .052 = 5.56 inches, more if shooting a .308 with a 178-grain bullet at 1000, 151(12.5 ft) * .052 = 8 inches. 3 degrees is not much and would be easily ignored without a bubble level on the scope.</p><p></p><p>This is only an estimator. Most of my rodent shooting is at or under 600 yards &having a flat shooting bullet minimizes the cant effect. The .224 75 ELDM at 3150 is an aim forgiving bullet & a cheap round to shoot.</p><p></p><p>I have seen estimators that multiply the mid-range trajectory by 4 then multiply that by the sine value - this may or may not correct but I think this would give an inflated value, like for a 168 HpBt at 2550 at 600, 3 degree cant, .052*152 (38*4) = 7.9 inches vs 2 inches. I have not seen this. </p><p></p><p>Having a pocket calculator with trig functions is handy item, like if a rodent is on top of a 100 ft high cliff, 600 yards away, what is the elevation angle. When Hannibal Lector (of nobility) was a little kid he calculated the height of a tower in his family's castle using the tower's shadow & protractor then paced off distance. Good for MOA & MIL Rad solutions & down & uphill shooting also.</p></blockquote><p></p>
[QUOTE="Hugnot, post: 2623797, member: 115658"] More info: From Accurate Shooter... [URL unfurl="true"]https://www.accurateshooter.com/optics/canting-effect-on-point-of-impact/[/URL] My estimator: A quicky estimator is to multiply the height of trajectory above line of sight by the sine of cant to give offset. Like for a .22-.250 75 ELD, MV 3150 at 600 yards sighted in at that range would have a mid-range trajectory of about 24 inches at 320-330 yards. Then 24 * .052(sin 3 degrees) = 1.24 inches offset. For 5 degrees the offset for same range & ammo would be .087 (sin 5 deg) * 24 = 2.088 inches. For a .308 W shooting a 168 hpbt at 2550 fps with a 600 zero, the mid-range trajectory would be 38 inches and the 3-degree cant offset would be .052 (sin 3 deg) * 38 = 1.976 ~ 2 inches, enough to miss an X. Speed makes for flatter trajectories. For a 300 WM with a 200 ELDX at 2800 fps at 1000 yards the mid-range trajectory would be 107 inches or just under 9 feet. The offset for a 3-degree cant would be 107 * .052 = 5.56 inches, more if shooting a .308 with a 178-grain bullet at 1000, 151(12.5 ft) * .052 = 8 inches. 3 degrees is not much and would be easily ignored without a bubble level on the scope. This is only an estimator. Most of my rodent shooting is at or under 600 yards &having a flat shooting bullet minimizes the cant effect. The .224 75 ELDM at 3150 is an aim forgiving bullet & a cheap round to shoot. I have seen estimators that multiply the mid-range trajectory by 4 then multiply that by the sine value - this may or may not correct but I think this would give an inflated value, like for a 168 HpBt at 2550 at 600, 3 degree cant, .052*152 (38*4) = 7.9 inches vs 2 inches. I have not seen this. Having a pocket calculator with trig functions is handy item, like if a rodent is on top of a 100 ft high cliff, 600 yards away, what is the elevation angle. When Hannibal Lector (of nobility) was a little kid he calculated the height of a tower in his family's castle using the tower's shadow & protractor then paced off distance. Good for MOA & MIL Rad solutions & down & uphill shooting also. [/QUOTE]
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