What Are the Four Primer Sizes?

Primer sizes can be broken down as follows:

1. Small rifle primers – which are about .175 inches in diameter and .120 inches tall.
2. Small pistol primers – which are about the same size as small rifle primers but designed specifically for handguns.
3. Large rifle primers – which measure about .128 inches in height and .212 inches in width.
4. Large pistol primers – which are an average of .120 inches tall and.212 inches wide.

Don’t Let the Names of the Primer Sizes Fool You

It may not always be obvious which type of primer is right for a given firearm. In some cases, large rifle ammo does not always use large rifle primers. For example, there are many styles of 308 Winchester that come factory loaded with small rifle primers instead.

The same is true when it comes to handgun ammunition. For example, Federal .45 ACP ammo often uses small pistol primers to propel one of the largest calibers on earth.

To avoid mistakes that could lead to improper loading or inaccurate shooting, you should always follow the directions in your reloading manual to the letter.

Sizes and Standards Can Vary Across Ammo Manufacturers

Every ammo maker uses its own proprietary processes to manufacture a particular caliber or type of ammunition. As a result, there are small but measurable differences in the actual products that each company turns out.

This accounts for the frustration many reloaders feel when certain types of primers cause their reloading press to jam. If you run into this problem, then try a different brand of primer and see if that resolves the issue.

Sometimes, tiny variations between brands of primer actually benefit the gun owner. For example, the thin cups used in Federal primers make them a good choice for cowboy action shooters. That’s because they compensate for the light hammer falls that accompany rapid-fire shooting styles.

Are Bench Rest/Match-Grade Primers Worth the Extra Cost?

Bench rest primers are designed to give consistent results from one round to the next. This is a major advantage in long-range or competitive shooting, where minor differences in a primer’s discharge can have major effects on where the bullet ends up.

On the other hand, when it comes to everyday shooting the benefits of using bench rest primers are less obvious. That’s because many factors can affect the accuracy and range of your shots, including weather, the condition of your firearm, and your skills as a marksman.

The bottom line is that standard primers are fine for most purposes.

Powder Valley: The One-Stop Source for All Your Reloading Supplies

Here at Powder Valley, we carry everything you need to set up and maintain your personal reloading workshop, including reloading primers. We sell all the best brands, and our customer service is unbeatable.

Browse our site, place your order, and enjoy fast delivery. Remember, we can help you to shoot more and pay less.