The subject of chronographs and by extension, exterior ballistics can be a daunting one. Now, what's so hard or complicated about explaining the nomenclature and functions of a chronograph you ask? Nothing, if that is all you wanted to read about. But the way it works is only part of the subject. The other facet of the subject relates to the meat of the matter-accuracy.

O.K. We can get a lot of neat information from a chronograph. But, what does it all really mean? More importantly, why is it important to you. The short answer is that using a chronograph will make you realize that you are a better shot than you think you are, regardless of the type of arm that you shoot.

To coin a phase, Arms Control can be defined as one or more consistently well placed shots. The key words are control and consistency. After all, you control the arm. Consistency helps you to hit what you are aiming at, time after time. Control is knowledge. Consistency is the correct application of knowledge. And, a chronograph is a diagnostic tool that gives you much of the information (knowledge) that is critical to controlling accuracy.

This is true regardless of the type of arm you shoot, be it a rifle, pistol, shotgun, airgun or bow and arrow. The physical rules for velocity and trajectory are always the same. So, let's discuss this point by looking at a specific velocity range-1200 feet per second.

This velocity range has always intrigued me because it relates to so many arms and calibers, from the .22 LR rimfire, all the way through most of the pistol calibers, shotguns (three dram equivalent heavy trap loads) and into low velocity riffle loads for the 45-70.

U.S. firearms and ammunition industries estimate that approximately three to four billion rounds of .22 rimfire ammunition are consumed domestically every year. That is the equivalent of about twelve rounds for every man, woman and child in this country, regardless of age, shooter or nonshooter. That is a lot of ammunition no matter how you look at it. The majority of it is .22 Long Rifle, high velocity, with a 36 grain bullet. Shoot this ammo through a rifle with a 20 inch barrel and you get a velocity of, you guessed it, approximately 1200 F.P.S.

An increase or decrease of 100 F.P.S. at 50 feet will vary your point of impact vertically by 1/4 inch. That's 3/4 inch at 50 yards, and so on. If you are a small game hunter, shoot small-bore Siluetas, trap or I.P.S.C. that is enough to make you miss your target.

How do I know this? My ProChrono Plus chronograph, target and a ruler showed me. The following target will illustrate the point. The results shown are typical of what you can expect with "fieldgrade" ammunition and can be readily duplicated.

This five shot group measures .546" vertically, edge to edge. Three shots went into a single hole measuring .215 by .185" (due to paper expansion and contraction), with an average velocity of 1210 F.P.S. One round shot almost exactly 1/4 inch high at 1158 F.P.S.

This string had an average velocity of 1222 F.P.S., a standard deviation of 6 F.P.S. and an extreme spread of 162 F.P.S., according to my Pro Prochrono Plus. All this translates into three rounds dead-on at fifty yards, one shot approximately 3/4" low and one about a third of an inch high. This is one potential miss out of five (20%) without and error being made on the part of the shooter.

Is this enough information to control consistent accuracy? No, not really. Like most statistical information, the more input that you provide, the more accurate the results. One five-shot string is better than none. Five five-shot strings is better. Remember how knowledge equates to control and consistency to accuracy?

Let me be very frank with you. I just happen to be fortunate enough to be able to combine something that I love (shooting) with something that I do fairly well (writing) and get paid for it.

This is an advantage for me in that it keeps everything in a realistic perspective. I try to look at things through your eyes and use the gear that most of you would use. This provides me with a more honest and accurate perspective of what I am doing.

I use the Prochrono Plus chronograph, made by Competition Electronic exclusively and have since it came on the market. In fact, I use two, (the second unit for checking terminal velocities) and will continue until a "better" unit comes out. When it does, I will bet that it will be from the same company, Competition Electronics. And, no, I'm not getting paid to tell you this part.

A part of my income is derived from my work with chronographs. There are several things that I look for when selecting one:

• Consistent and reliable operation.
• A LARGE shooting area (this model has TWICE the shooting area of comparable makes) and affordability.
• A good selection of accessories, such as a printer, remote control and an illuminator to help with indoor use.
   

I have no difficulty in suggesting that you take a close look at chronographs in general and the Prochrono Plus in particular. Getting this kind of diagnostic tool for around $100.00 is a real bargain.

You may be able to pay more for a chronograph buy you will not get a better value.

Every shooter should have on available to him or her. Using this kind of instrument will give you significantly better control, consistency and accuracy. And, it's made here in the U.S.A.

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Copywrite: 1996, Richard N. Anderson