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|02-01-2010, 02:48 PM||#1|
Join Date: Nov 2009
Caliber comparison, maximum point blank range
By now the skeptics, doubters, and competitive high power shooters are thinking I?m crazy and asking questions. How can this be? How does this work? Why don?t you sight in at 100, or 150 yards? Read on. In Missouri, the majority of white tail deer are killed at less than 100 yards, due to brush, hills, and terrain, few deer are killed between 100 and 200 yards, and rarely at distances beyond that. The conventional wisdom for a chest shot on a deer is accepted as a 12? circle but for this article lets assume it is only 8?. Deer are 3-dimensional, alive and moving and have little in common with a two-dimensional paper target. The objective is to place a bullet anywhere within an imaginary 8? circle in the deer?s chest area. I have never seen a live deer imprinted with an 8? bullseye target however I did see such a thing in a cartoon where two deer were talking. The punch line was ?Bummer of a birthmark, Dude!?
Next let?s pick eight of the most common calibers and cartridges used to deer hunt in Missouri and determine their point blank range with a zero of 25 yards. I determined the selection of cartridges by the semi-scientific method of supply and demand. I visited Wal-Mart in Eureka, MO, noting what ammo was on sale in bulk at the deer hunting gear isle. From smallest to largest the calibers are: 1).223 Remington, 2) .243 Winchester, 3) .270 Winchester, 4) 7mm Remington Magnum 5) 7.62 X 39, 6) 30-30 Winchester, 7) .308 Winchester, 8) 30-06 Springfield. I had my friend Jeff Chosid a nationally renowned highpower competitive shooter, and author, run ballistic data for me using Sierra Infinity Ballistics software. Jeff also has a small business called C.A.B. Designs that produces standard and custom wind charts. Check them out at windcharts.com. The ballistic charts were plotted by Jeremy Hogue.
First on our list the Remington .223 , a varmint and military cartridge, at 700 fps faster than our 2500 fps threshold, we would expect that it shoots flat and it does. Using a 55 grain bullet and a 25 yard zero, the bullet is never 3 ¾ inches above or below the point of aim out to 300 yards. The bullet also crosses zero at just past 250 yards. Therefore the point blank range for the .223 is from 0 to 300 yards. To kill a deer you simply aim at the imaginary 8? circle and pull the trigger, with no hold over or under to worry about. Before you trade in your old .35 Remington remember that while the .223 shoots flat, it is still only a .22 caliber. It is the minimum sized, legal cartridge for deer, and many experienced hunters however would consider it a poor choice.
The Remington .243 is a much better pick. Based on the .308 this 6mm shoots flatter than the .223 and with almost twice the bullet weight at 100 grains. With a 25 yard zero, this cartridge also has a 300 yard point blank range. The maximum rise of the bullet is under 3 ½ inches at 150 yards and just below 3 ¾ inches at 300 yards. From varmints to deer this caliber is an excellent choice, especially if low recoil is an important consideration.
The old and reliable .270 Winchester is also an excellent choice. It is flatter shooting than it?s parent the ubiquitous 30-06, but not as effective on big game like elk and moose, which is not a problem in our state. Using a 150 grain bullet, and a 25 yard zero we have a point blank range of over 300 yards. The top of our trajectory is 3.83 inches at 150 yards and 1.40 inches low at 300 yards.
The 7mm Remington Magnum has much more power than needed for Missouri?s whitetail hunter but its flat shooting and long range capability make it an excellent ?bean field rifle?. Using a 25 yard zero and firing a 150 grain bullet the trajectory is very similar to the non magnum 270. This cartridge also has a point blank range of 300 yards with the maximum bullet rise of 3 ¾ inches and a maximum fall of slightly more than 1 ½ inches. At 300 yards. Perhaps more interesting is there is no significant advantage over the old 270 except the potential for shooting slightly heavier bullets.
The next two calibers I will talk about are the venerable 30-30 and the 7.62 X 39 Russian. Both these cartridges when compared together are within fractions of an inch on the ballistic table and both are a little below our 2500 fps threshold. The 30-30 was designed before 1900 and the 7.62 X 39 was designed for the SKS carbine in 1945. Both cartridges, the 30-30 with a 150 grain bullet and the 7.62 X 39 with a 123 grain bullet are adequate for a point blank range of 0 to 200 yards when sighted in at 25 yards. Additionally both cartridges are also near zero at 150 yards and never rise more than 2 inches above zero.
The .308 Winchester and the 30-06 Springfield are as similar to each other ballistically speaking as the previous two cartridges. Coincidentally the .308 is also about 50 years younger than the 30-06. These cartridges were designed for the military and both have proven records as big game takers in North America. Both offer a wide variety of factory loaded ammunition in different bullet weights and styles. With a 25 yard zero and bullets between 150 and 165 grains both will have point blank ranges of 0 to 250 yards.
In researching this article I not only proved a 25 yard zero works, I discovered several interesting points. I never would have believed a 30-30, and a 7.62 X 39 would shoot flatter at 200 yards than a 7mm Rem. Mag, or a 243 at 300 yards, but they do. I also never realized how ballisticlly similar the following cartridges are: a 30-30 and a 7.62 X39, a 270 and a 7mm Rem Mag., and a 308 and a 30-06. Furthermore I do not see much advantage of a 7mm Rem. Mag. over the much older and less glamorous 270. Now here are at least four separate arguments you can bring up at deer camp 2005, just make sure you have this copy of Missouri Deer Hunter Magazine to prove your point. My thanks to Bill Kunz for the inspiration and motivation to write this article.
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