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Old April 20, 2013, 05:51 AM   #96
Bart B.
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Join Date: February 15, 2009
Posts: 4,804
Speaking of wind bucking bullets for the .308 Win., consider Sierra's HPMK's of 240 and 250 grain weights. Leaving at about 2150 fps from a 1:8 twist barrel, they'll drift less than any lesser weight HPMK at 1000 yards. And they stay supersonic to about 1200 yards.

Speaking of minutes of angle, note that in the beginning, when the shooting Gods in the USA decided smallbore and high power target scoring rings would be even inches in their diameters (late 1800's), one minute of angle was standardized as exactly one inch per hundred yards of range. Telescopic sights were made with a 7.2 inch external adjustment mounts that had .002" movement over 4 clicks of their 40 tpi adjustment screws. That's exactly 1/3600th the distance between the mounts. 1/3600 the distance of 100 yards is exactly 1 inch. Standard metallic sight spacing was 30 inches, so rear sights had .008333 inch movement for 1/3rd turn of the knob which happens with 40 tpi threads; very common on USA made aperture rear sights. 1/3600th of 30 inches is also .008333 inch. 'Twas only after some folks couldn't figure this simple and easy to use method out that the trigonometry value of a MOA of about 1.0472 inch per hundred yards became both popular and much harder to mentally use.
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Last edited by Bart B.; April 20, 2013 at 06:01 AM.
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