X-Ring Newsletter

The X-Ring

Technical Newsletter From Your Ballistic Technicians

Volume 5, Issue 1

The ABC's of BC (part 2)
by Rich Machholz

A couple of issues ago, I tried to illustrate the need to pick the proper bullet for expansion characteristics rather than BC for normal hunting ranges. It clearly shows there is very little practical difference in bullet drop from a 200 yard zero throughout the entire range, including 300 yards.

This time lets look at the real nemesis....wind at extreme range. I stayed with the 30-06 and 180 grain bullets at 2700 fps. By plotting all three bullet types (RN, SPT and SBT) for trajectory all the way to 500 yards with the Sierra III Exterior Ballistic computer software program, we get a very clear picture of which style bullet does best at these long ranges. I used a conservative wind speed of 10 mph.

 

 

  RoundNose
ProHunter
Spitzer
ProHunter
SpitzerBoattail
GameKing
Range 180 grain 180 grain 180 grain
100 yards 1.2" 0.8" 0.7"
200 yards 5.2" 3.4" 2.8"
300 yards 12.2" 8.1" 6.4"
400 yards 22.5" 15.0" 11.8"
500 yards 36.6" 24.5" 19.2"

What we see now is that bullet drop or trajectory isn't very much of a factor under field conditions at normal hunting ranges and wind isn't either at 200 yards or less. But, at 300 yards and beyond it is a major consideration. It becomes abundantly clear that for the long range shooter (300 yards and beyond) proper bullet shape is not only desirable but absolutely essential.

 

Sierra's 4th Edition Reloading Manuals on CD-Rom

Sierra is proud to introduce the multimedia version of our highly acclaimed 4th Edition Rifle and Handgun Reloading Manuals on CD-Rom. This program has been certified as Windows NT(r) and Windows(r) 95 compliant through the very stringent Microsoft(r) Software Logo Program and is available now for $39.95.

The program contains all of the articles and photos from both the rifle and handgun manuals. Additionally, the navigation of the program allows for the jumping between loading data, exterior ballistic tables, and bullet descriptions with the click of a button. Included is a built in Internet browser (you must have your own Internet access account). Audio and video clips from our reloading videos enhance the program.

Finally, we have gained permission from Burris Sports Optics to include the Burris Varminter prairie dog hunting game on our program. Call 1-800-223-8799 to order your CD-Rom.

 

Double Duty for Dual "X's"
by Paul Box

By far the most popular reticle today is the dual X, but most hunters don't take full advantage of its' value.

Our hunter, we'll call Steve, has the ever popular 3x9 scope on his rifle with a dual X reticle. By simply taking a large piece of white poster board and drawing broad lines with a black marker one inch apart, then placing it at one hundred yards, Steve can lay his rifle on a bench rest and by placing the cross hair intersection on the top line, count the number of lines it takes to fill up the gap to the thick section of the vertical wire. If his scope is set at 6 power and it covers five inches, then he can multiply five by each one hundred yards to give him the distance. If he wants to know the value at other powers, this is a good time to check and write it down for later reference. (make certain you check and measure your scope)

Steve also knows that the average whitetail buck in his area measures eighteen inches from brisket to the top of his shoulder. If Steve spots a deer across a picked corn field and it neatly fills the gap in his dual X, this deer is approximately 350 yards. Now Steve can hold according to his rifles trajectory.

 

Short Shots
by Carroll Pilant

When finished reloading, always remove the powder from your measure and return it to the original container. Several firearms are wrecked each year from handloaders forgetting there was a few charges left in the measure before adding another powder. Also, you won't have powder left in that you have forgotten what it is; plus, it will be in an airtight container to help maintain its' correct burning rate.


Windflag, What Windflag??
by Tommy Todd

When comparing loads for your rifle, be it a .30-06 deer rifle or your one-hole punching .22-250, you better be watching the wind flags. Pay less attention to the flag at the target and more attention to the one just in front of you. This is because the wind will affect the bullet more, closer to the muzzle.

Watch for "standard" wind condition and try to shoot whenever you recognize this condition on the flags. If the wind is around 10 mph or less, you should be able to distinguish mirage and utilize it as a wind indicator.

 

Q.How did you establish your accuracy load in your reloading manuals?
A. These are loads that have a proven history of working well in many rifles. They generally provide a high level of accuracy in many different barrels, not just our test barrel.


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