The Science Behind Reloading: Why Do We Reload?


Why Should You Reload?

In long-range shooting we face a lot of unknown variables. The most effective shooters in our community can effectively take into account all of these ever-changing variables to get their rounds on target with accuracy and consistency. Between the wind, humidity, temperature, Density Altitude, and actual range to target we have a lot of information to account for. A common suggestion to those looking to get the most out of their rifle is to reload. The reason is really simple, and it isn’t to save you any money. It is to find the best possible choice for your specific rifle.


When we look at commercial ammunition we are talking about a mass-produced batch. While some companies do a better job than others you are likely to find variations between lot to lot. If we look at the fundamentals of shooting as a comparison such variations in commercial ammunition can cause inconsistent results much like jerking the trigger. Commercial ammunition from the same company and lot are likely to use the same power and bullet combinations. Every rifle is different, and some might not agree or be getting the best combination of powder and bullet to maximize your rifles accuracy.

ES and SD

If you have ever looked around on the internet in regards to reloading ES and SD have probably come up.  So what are they are why are they so important?

ES stands for your extreme spread. It is the difference between your fastest and slowest chronograph round. The lower your ES is the more consistent your ammunition is.  The higher your ES is the more inconsistent the ammunition is. However a single round loaded improperly can throw this number as it samples your fastest and slowest moving rounds ONLY.

SD stands for standard deviation.  The standard deviation will tell us how consistent or alike your ammunition is. To explain this simply this will let you know how close your shots are to the average. Much like ES the lower your SD the more consistent your ammunition is shot to shot.  It is worth noting that the majority of experienced reloaders recommend shooting a minimum of 20 shots when calculating your SD.

One thing that all long-range shooters should invest in regardless of reloading is a chronograph that does all the math for you. Finding your average muzzle velocity and ES can easily be done on a standard calculator. SD is something that takes a little more math skills. We recently did a review on the MagnetoSpeed V3 and recommend it highly.

Load Development

There is no short cut in developing a load that will work best with your rifle. Asking online for other people’s data is not the right answer and can be down right dangerous. Do the work the right way and you will get better results. Period.

Powder and charge weight

There are a lot of powders out there. Some burn faster than others. When you reload you can control what powder you use and also how much powder you use. By finding a powder that your rifle likes best with a charge weight that gets the best accuracy (not velocity) you can find an improved load over commercial ammunition and get more accuracy from your rifle,


Most commercial ammunition is loaded to a predetermined C.O.L. or cartridge overall length. By reloading your own ammunition you can adjust how close the bullet is to the lands of your barrel. Some bullets perform better at a different distance then others. This will help get even more accuracy out of your reloads per your specific rifles barrel and the bullet you are shooting.


when reloading you can choose the quality of your brass. Some manufactures are known to make better brass than others. The better the brass the more reloads you can get out of it. The better brass tends to have more consistent tolerances. The more consistent the tolerances are the more consistent your ammunition will be in the accuracy department.


Reloading is as much as an investment as your rifle and gear. It pays to get quality equipment upfront. Quality match grade dies can allow you to accurately and consistently seat the bullet to the same depth. A quality powder measuring system will allow you to precisely measure powder for consistent results.  Even with the most consistent process in reloading the quality of the equipment used plays a huge part in your overall results.


Not all rifles will like the same ammunition, and one of the key things of reloading is consistency. It is not something that should be rushed. The more consistent process you have while reloading your own ammunition the more consistent your ammunition will be when it comes time to shoot it.

If you would like more information on reloading or getting started please feel free to reach out to us!

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