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Old February 1, 2014, 10:54 AM   #60
Senior Member
Join Date: October 18, 2006
Posts: 7,089
Real Gun,

Here is and article on how you can calculate a point blank zero:

Using the numbers for a 45 Colt, 200gr Sierra match bullet at 1400 fps (from a 20" 1892 carbine), with an 8 inch vital zone to set the pipe, (the bullet can't fly more than 4" above or below line of sight), the 45 Colt gets a max PBR of 175 yards, with 407 ft/lbs of energy remaining. 300 ft/lbs is the recommended minimum for big game in the 200 lb class, so it should provide a good thumping on deer, pig, coyotes, etc.

Swap the bullet for a 300 gr Sierra sports master (at 1300 fps), and you still get a 175 yard max pbr zero, but now your bullet whacks critters with 677 ft lbs of energy, moving up to what I would consider good minimum for a 300~400 pound game class (heavy mule deer, black bear for example).

You can check it out for yourself using jbmballistics trajectory calculator. Set the "Vital Zone" to the size of your "pipe" and then check the "zero at max point blank range" option and it will show you your pipe zero.

Machine guns are awesome until you have to carry one.
Jimro is offline  
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