Most shooters know to expect the first shot from a clean barrel to be outside the usual group. Sometimes it’s more than one shot. The amount of this change, and the number of rounds necessary to overcome it, can vary widely depending on ammunition, cleaning methods and so on. I am not normally going to the 600-yard line with a clean barrel, but that’s often the case when I attend a Long Range Rifle event.

Anything that can be done to enhance early-shot consistency is extremely valuable. To that end, I have determined three influences that start back in the shop and one that’s now done on the firing line.

I’m convinced that it is unwise to mix loads--using bullets from a different maker at more than one event on the same day or using a different propellant brand or type in the same way. I learned this through a good deal of testing at 1,000 yards.

I always use the same brand bullet and very same propellant for all my loads. It’s okay to change bullet weights, just as long as they’re built on the same jacket material. Never mix coated and uncoated bullets. Your zero will return but not right away, and it’s “right away” that matters when faced with a sighting shot.

I have long been a proponent of coated bullets but have recently changed my material preference from moly to boron-nitride. BN coating goes on clear and seems to have none of the drawbacks some claim for moly. Performance increases are virtually identical.

The unexpected side benefit I have found from BN coating is that my first shot from a clean barrel goes onto the same point as my last shot in an event. That, especially on the 1,000-yard line, is worth at least a “half a sighter,” maybe more. I’m using nothing but BN-coated bullets now and likewise have geared my own ammunition company toward producing them.

Over the past three years, I have come to rely much more on mathematics to help me determine my first-shot zero. I am not, however, using a conventional ballistics program. A colleague and I developed a more accurate and comprehensive system that can encapsulate condition influences without doing any “math” on the spot. All calculations have been done previously.

Essentially, I have been factoring density-altitude into my initial corrections and have, especially in Long Range Rifle events, been fantastically happy with the results. My first shots are now much closer to my last ones.

I’m using custom-done charts and carry these with me to every event. Learning to use the density-altitude factor answers questions of how temperature and altitude will influence bullet impact. It allows you to precisely determine, for instance, what will happen when it’s 90 degrees one day and 65 the next, as can be the case at Camp Perry.