Primers

There are 2 different types of Primers.

Berden Primer
Boxer Primer

Berden Primer : Developed by an American, Col. Hiram Berdan. The priming system used in England and throughout much of the rest of the world. Utilizes an integral anvil, formed into the base of the primer pocket. Have two or more smaller flash holes, located at various points around the anvil. This makes it impossible to decap Berdan cases as easily and efficiently as Boxer primed cases.

Boxer Primer : Invented by an English ordnance officer, Col. Edward Boxer. The predominant priming system used here in the U.S. The anvil is a separate piece affixed into the primer’s cup, and bottoming out in the primer pocket when the primer is seated. A single, fairly large, centrally located flash hole, making them eminently suitable for reloading.

Source : http://www.exteriorballistics.com/reloadbasics/primer.cfm






Centerfire primers are made up of 8 different degree of burn rates, however, there is only 4 catagory of primers, rifle, rifle magnum, pistol and pistol magnum.

Large Rifle Primers
Large Rifle Magnum Primers
Small Rifle Primers
Small Rifle Magnum Primers

Large Pistol Primers
Large Pistol Magnum Primers
Small Pistol Primers
Small Pistol Magnum Primers

These Primers are of the same diameter, (Large Primers .210 Diameter : Small Primers .175 Diameter) yet, can not be switched back and forth.

Pistol Primers are to be used for Pistols and Rifle Primers are to be used for Rifle.

Source for the following : http://www.chuckhawks.com/primers.htm

Rifle primers use tougher cups than pistol primers because the firing pin blow of rifles is usually harder than the firing pin blow of pistols. Rifle primers also contain more priming compound than pistol primers, since rifle cartridges typically contain more powder than pistol cartridges.

Magnum primers are "hotter" than standard primers. It is recommended that magnum primers be used with ball (or spherical) powders, when loading magnum or other large capacity cases, and when it is anticipated that the cartridges will be used at temperatures below 20 degrees F. Ball powders are generally harder to ignite than flake and extruded powders and magnum primers are often called for, even in non-magnum rifle and pistol cartridges. Always refer back to your reloading manual for the proper primers.

Primers for Shotguns

All U.S. made shotshell primers are designated #209, regardless of company of manufacture. #209 primers are used for all shotgun gauges. They are known as "battery-cup" type primers. This is a two-part primer design in which the anvil and primer cup are supported in an external cup. Shotshell primers are larger and shaped differently than metallic centerfire primers. This makes them immediately identifiable. The two types cannot be interchanged or confused.


Primers affect the pressure generated by the cartridge. Changing from standard to magnum primers can change the pressures of the cartridge. Changing brands but using the same type of primer will also usually result in pressure changes, but ordinarily these will be less drastic. It is reccomended that you use the correct primer for the correct load data from your manual.

The general rule of thumb when changing brand of primers, or using a magnum primer in place of a standard primer, is to reduce the load by 10% of the published starting load. Using a magnum primer in place of a standard primer should be done with extreme caution. Especially if you are near max load. Using a magnum primer in place of a standard primer at the max level is extremely dangerous and can cause the pressure to be too much for the cartridge and cause the cartridge to explode in your chamber.

When reloading, always seat primers slightly below flush with the head of the cartridge case. This insures that the anvil is properly pressed against the priming compound for reliable ignition. Failure to properly seat primers is the biggest single cause of misfires in reloaded ammunition. A good depth to aim for is .005" below flush. With some experience this can be determined by feeling the case head after the primer is seated. Any primer that is flush or protruding should be very carefully removed and the case reprimed. Decapping a live primer can set the thing off, so behave accordingly and take all necessary precautions, including ear and eye protection.

The following was copied from http://www.shootingtimes.com/ammunition/ST_mamotaip_200909/index1.html

A Myth-Conception
Like others who reloaded in the 1950s and ’60s, I heard the old mantra, “CCI primer cups are hard.” I used CCI primers long before I dreamed I’d be working for the company, and I never had problems. I had talked to other hand-loaders who claimed to have had some trouble. Arriving at CCI/Speer in 1987, I found out the real story.

The metal cups were neither harder nor softer than any other brand. However, the early noncorrosive primer mixes that xxxx Speer and Dr. Victor Jasitis developed had one difference from many other primer products at the time—the dried pellet was rather brittle. This was not a problem unless the loader tried seating primers too deeply; in that case the anvil was forced almost to the cup, and the brittle pellet broke away from the anvil. With little mix under the tip of the overseated anvil, a misfire was lurking. I decided the reason I never had a problem was that I seated off-press with hand tools that let me feel the seating.

The mix that did not like overseating was retired years before I arrived in Lewiston. It just goes to show how old perceptions can linger even in the face of data and facts.

This is just a quick over view of primers. There are alot more information that can be expressed such as military style primers for Nato rounds and BMG rounds. If there are any further questions on Primers, feel free to start a thread and we all will work hard on getting you the most safe and best answer for your application.

If anyone else have anything to add to the Primer list, I invite you to do so. There are compatibility charts that can be found if you google for them and using your Manual is the one most important and best place for information.

Never substitute anyting in place of your Reloading Manual.

I have given Credit to the sites that I have received the information from. None of this information is soley from me.

Edited 1/1/2011

hey daywalker! what do you know about cci no 34 mil spec primers? I reloaded them in my 7.62 x 39 ammo with reduced reloads because i heard that they are like mag primers. I also called Hornady & the guy told me to load at 22.5g of H4198.

I have not loaded the No 35 milspec, I use wolf primers in my AR. I do know that the 7.62x39 needs them for the free floating firing pin to prevent slam fires..

I do not load for the 7.62x39. Not sure how close they are to being magnum. I am sure someone on the forum here tho would be able to tell you more about the number 34 cci's.....

Thanks. for the comment.

I have used them for 2 years and have never had any that slam fired. In bolt and 4 diffrent AR's. I used the powder that was listed in the book and the amount and had no trouble in any of are guns. I also use Rem benchrest primers.