What you're talikng about is a subtension calculation, all based on simple ratio and proportion calcs. As magnification changes so does reticle subtension in a linear manner. The calc. is inversely proportional tho, because the subtension decreases as magnification increases.

Fortunately since we aren't actually changing magnification here it's simply directly proportional. Suppose the 16" target is 600 yds. away, u have the following equation-- 16/600=8/X, so X=300 yds.

Another way to compute it is too use a modified mil-dot ranging formula, i.e.-- target size in inches X 100/reticle subtension in inches = X/ # of reticle units, or 16 X 100/say 2.7"= X/1 reticle unit== 592 yds. Now an 8" target fills that same 2.7" gap measurement, so now u have 8 X 100/2.7= X/1 reticle unit== 296 yds.

All reticle subtension formulas are based off the same linear concept, which makes them extremely flexible to fit many different scenarios, and fun to play with. The Leupold system is based on a 100 yd. gap measurement (x-hair-plex post) of 2.7" for a 16" target @ 600 yds. @ THE HIGHEST MAGNIFICATION since 2.7" X 6== 16.2", then as the magnification is lowered the subtension gets bigger to "gap" a 16" back-brisket deer that's closer. Hope this isn't too confusing an explanation.

[ 10-31-2004: Message edited by: sscoyote ]

[ 10-31-2004: Message edited by: sscoyote ]

[ 10-31-2004: Message edited by: sscoyote ]