Barrel Movement- Part 2

In part one of this multi-part series, we looked at the theory behind harmonics and how barrel movement can greatly affect a shot’s accuracy. In Part two, we will begin to look at load development and how to create the most accurate load by taking barrel movement into consideration when reloading brass.

Importance of a Chronograph before getting started.

In the days of yore (BC -- before chronographs), it was necessary to blindly hunt for loads that worked. Once a good load was found, changing any component could render the whole process useless (since changing components varies pressure and velocity) and one pretty much had to start from scratch if anything changed. A chronograph provides direct insight into what your loads are doing, and what you need to do to make them work better. You will be able to immediately determine if a changed component produces velocity outside of the range the barrel likes. In most cases simply adjusting the powder charge will correct the problem.

If you are looking at reloading your own brass for the purpose of accuracy and consistent loads, having a good chronograph is essential to the process. It is important that you find one that is extremely accurate and stable, as well as one that uses infrared sensors that will detect the bullet under any circumstances, such as total darkness, when other chronographs might fail to pick it up. Which chronograph to go with should be a decision made from much research and reading of reviews and choose the one best suited for your budget and needs.

Load Development

Step One

Let’s start from scratch and assume nothing is known about reloading brass for a particular firearm. The only information we have is from load manuals. Also, time is valuable, since we probably don't have a range in our back yard. Even if we are lucky enough to have a place to shoot outside the back door, saving time by doing things efficiently lets us enjoy other things in life. We will also assume that your rifle's bore is clean and free from copper fouling, that your barrel's bedding is correct, and that all screws are tight on your rifle. Another thing to keep in mind is that it often takes several "fouling" shots from a clean barrel for velocities to stabilize so you should fire a couple of fouling shots before starting load development.

Most reloading manuals list their loads starting with the fastest powders and work down to the slower powders. The powders have been selected as suitable based in part on the loading density so any of the powders should work well. If you are starting out by having to purchase powder, select one of the powders in the middle or slow end of the loading data list suitable for the bullet you will be using. This will give you “wiggle room” to move up or down, depending on the data you begin collecting in your loads.

At your reloading bench, begin by preparing the reloading brass for reloading. Sort your brass by brand or military manufacturer/date head stamp. Clean, resize, trim (nominally to .01" less than the maximum allowable case length as specified in your load manual--the actual length is not as important as is the lengths being uniform), and prime about 100 pieces of the same brand of brass with your favorite primer. (The brand of components you use are not important at this point as long as all the cases are the same brand or military manufacturer/date head stamp and you use the same primers and bullets for all the cases.)

When we pick up in part three, we will look at powder choices and take our load a step further.