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411man
06-11-2008, 05:29 PM
Part 1


Someone has needed to post this information for a long time so everyone would have a source to go to for information on these items so much a part of ammunition and reloading.

First some general information on primers.

http://www.chuckhawks.com/primers.htm

Primers, the Sparkplug of Centerfire Cartridges

By Chuck Hawks



The primer ignites the main powder charge in the cartridge case. Without a good primer, nothing happens when a gun's firing pin falls. All ammunition commercially loaded in the U.S., as well as reloaded ammunition, uses the self-contained "Boxer" type primer, developed by Edward Boxer. This little device has a cup, which holds the priming compound, and an anvil. The anvil rests lightly on the priming pellet, which is crushed between the dent made by the impact of the firing pin and the anvil to initiate ignition.

European cartridges have traditionally used primers of the "Berdan" type, developed by Hiram Berdan, which lack the anvil of a Boxer primer. In a cartridge designed for a Berdan primer the anvil is built into the primer pocket of the case, rather than the primer. These cases can not be de-capped and reloaded by standard reloading tools. I understand that, as reloading catches on with European shooters, an increasing number of European cartridges are being factory loaded with Boxer primers.

It is a quirk of history that Edward Boxer was a British ordinance officer, yet his primer design was adopted in the U.S. Hiram Berdan was an American ordinance officer, yet his primer design was adopted in Europe, as well as most of the rest of the world.

The priming compound itself is an explosive intended to be detonated by percussion. (It can also be detonated by heat or flame.) There is typically less than one grain of priming compound in even the hottest primers. Never the less, primers must be handled and stored carefully. They are, after all, designed to start a fire. Store primers in the proverbial cool, dry place away from other flammables. High humidity degrades primers more than high temperature. According to CCI/Speer, properly stored primers will remain viable for decades.

Keep different types of primers separated so that they cannot be confused. Always store primers in their original packaging, which is designed for safety. Never store primers in bulk, such as in a can or jar. In many jurisdictions it is illegal to store more than 10,000 primers in a private home.

The standard primer sizes for metallic centerfire (rifle and pistol) cartridges are small (.175" diameter) and large (.210" diameter). The standard primer types are pistol, pistol magnum, rifle, and rifle magnum.

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. CCI/Speer typically recommends 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. Let your reloading manual be your guide to primer selection.

The common primer brands encountered in the U.S. are CCI, Federal, Remington, and Winchester. I have used all four of these brands, and they are all perfectly satisfactory. In addition, RWS (Boxer type) primers are sometimes available in North America, and are common in Europe.

Each of these brands has their own designation for the specific type and size of metallic centerfire primer. Here are the standard primers by brand. (There are also a few match, bench rest, and mil-spec primers, which are not included here.)

CCI

Small pistol = 500
Small pistol magnum = 550
Large pistol = 300
Large pistol magnum = 350
Small rifle = 400
Small rifle magnum = 450
Large rifle = 200
Large rifle magnum = 250
Federal

Small pistol = 100
Small pistol magnum = 200
Large pistol = 150
Large pistol magnum = 155
Small rifle = 205
Small rifle magnum = 250M
Large rifle = 210
Large rifle magnum = 215
Remington

Small pistol = 1 1/2
Small pistol magnum = 5 1/2
Large pistol = 2 1/2
Small rifle = 6 1/2
Small rifle magnum = 7 1/2
Large rifle = 9 1/2
Large rifle magnum = 9 1/2M
Winchester

Small pistol = WSP
Small pistol magnum = WSPM
Large pistol = WLP
Large pistol magnum = WLP
Small rifle = WSR
Large rifle = WLR
Large rifle magnum = WLRM
RWS

Small pistol = 4031
Small pistol magnum = 4047
Large pistol = 5337
Small rifle = 4033
Large rifle = 5341
Large rifle magnum = 5333
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 may substantially raise the maximum average pressure of the cartridge and indiscriminate changes are not recommended. The A-Square Company conducted pressure tests involving six different primers. These tests used the 7mm Remington Magnum cartridge with a 160 grain Sierra BT bullet and 66.0 grains of H4831 powder and the results were reported in the A-Square reloading manual Any Shot You Want. A-Square used CCI 200 and 250, Federal 215, Remington 9 1/2M, and Winchester WLRM and WLR primers in these tests. They revealed a total spread in pressure of 12,800 psi from the mildest standard (the CCI 200) to the hottest magnum (WLRM) primer tested.

Changing brands but using the same type of primer will also usually result in pressure changes, but ordinarily these will be less drastic. In the A-Square tests the pressure spread between the CCI 200 and the hottest standard primer (the WLR) was 9600 psi. The spread between the mildest magnum primer (the Rem. 9 1/2M) and the hottest magnum primer (WLRM) was 8300 psi. These are significant pressure variations that cannot safely be disregarded.

Incidentally, these same tests revealed that the Federal 215 and CCI 250 large rifle magnum primers produced nearly identical pressures. The difference between these two primers was only 100 psi. A-Square also reported that, while they had not tested these two primers in all possible cartridges, this result was typical of their experience with these two primers.

Basically, I follow the recommendations of whatever reloading manual I am using as a reference regarding the proper brand and type of primer to use. For example, if the load in the manual was developed using a WLR large rifle primer, then that is what I use. If one brand of primer (of the same type) must be substituted for another, the conventional wisdom is to reduce the recommended powder charge by 10% (assuming the load is not already at the minimum) and work back up slowly.

I don't know how valid it is, but the opinion of many reloaders seems to be that Winchester primers are generally the "hottest," Federal and CCI are the middle brands, and Remington primers are the mildest. That is also my impression, but understand that it is based on rumor and supposition, not fact.

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.

For hunting and general recreational shooting purposes I have not ordinarily seen a significant difference in accuracy attributable to using different brands of primers. However, there are exceptions to this general observation. Some loads do seem to work better with a certain primer. Sometimes the chronographed standard deviation in the velocity of a load is lower with one brand of primer than with another. In such cases I just go with the flow and use whatever primer works best.

Modern primers are a marvel of ingenuity and production uniformity. The importance of these little cartridge "spark plugs" is often overlooked by recreational shooters--in itself a tribute to their reliability.

411man
06-11-2008, 05:31 PM
Part 2

Berdan

Now let's look at the differences between Berdan and Boxer primers.


Berdan primers are used in manufacture of Military spec ammunition while Boxer is used in civilian type ammunition.

While Boxer primers have a single hole for ignition Berdan uses two smaller holes forcing the ignition flash out at higher pressure producing greater reliability of ignition.

Berdan is much harder to decap and the process tends to cause deforming of the primer pocket much more than with Boxer type primers slo reloading cases is much more difficult.

Be sure to view the links as there are many pictures, charts, and illustrations to be reviewed.


Berdan Primers :


Berdan Primer Suppliers and Dimensions

http://www.dave-cushman.net/shot/berdan_supplies_dimensions.html

The "Berdan" primer system was invented by an American ordinance officer named Hiram Berdan, around 1870 is the nearest date that I could establish, ironically the system is used more in the UK, Australia, South Africa and Europe than the USA where it originated.

The primer is the source of ignition for the rapid burning process that occurs in firearms.

The whole process starts from the percussion blow of a hammer or firing pin. The metal cup of the primer is distorted by this striking action causing the compression of the primer compound between the cup's inner surface and the tip of the post, that is incorporated in the structure of the case, which acts as an "anvil".

The pocket that the primer is located in is of small volume and thus the expanding gasses and flame are forced through holes numbering one two or three that are placed in a ring surrounding the central anvil post. This causes one two or three jets of flame with a correspondingly larger surface area than the single flame of the Boxer system.

The "flash holes" of Berdan primer recesses are usually smaller in diameter than those used for the Boxer types. The total area of the Berdan flash holes is less than for boxer types, ensuring that the resulting jets of flame are more intense, thus giving more reliable ignition.

As the propellant powder usually consists of regularly shaped, discs, rods or tubes, there are interstitial spaces between the particles (and in the case of tubular grains along the internal axis as well). The flames from the primer holes percolate through the spaces, causing immediate ignition of a large surface area of many of the propellant grains. Some powders are also porous in themselves which further promotes this rapid ignition.

This multi flame approach works well with Nitro cellulose cylindrical rod propellant (Cordite) which because of it composed of long thin rods that are almost the full length of the space below the bullet. It presents a smaller overall surface area to the ignition flame front, but the long thin spaces between the rods allows for a great deal more of this surface area to be exposed to the multiple flames.

I make no apologies for using "imperial" dimensions on this page, as metric conversion can lead to discrepancies which may become dangerous.

The principle dimensions of Berdan primers for specific manufacturers and calibres are given on the companion page that also attempts to provide information on Berdan primer suppliers.

Some cups that are made of bronze contain priming compounds that are corrosive.

I personally favour Berdan primers over Boxer The reliability and safety are better and the reloadability is no different in difficulty. A different method is needed, but I have never understood why our American friends whinge about the "difficulty" or "impossibility" of reloading.

Many solid brass shotgun cartridges are Berdan primed and many of the Cordite "big game" cartridges are also Berdan type.

The terms 'primer' and 'cap' are often used interchangeably, but the word cap is used more frequently with reference to Berdan than Boxer.

Removal of spent Berdan primers is dealt with on a group of pages that link from Berdan Decapping.





Berdan Primer Dimensions

http://www.dave-cushman.net/shot/berdanprimers.html

Berdan Primers differ from the Boxer version, by virtue of having the anvil as part of the case, this simplifies the Berdan primer to an uncomplicated drawn cup containing a detonating compound. The comparison at right has been taken from a photo by Fred Schwaner and shows the Boxer case head and primer with three legged anvil on the left (note central hole). The central anvil post in the right hand head has two small flash holes flanking it that allow the ignition flames to be projected into the charge, the green primer compound is dimpled in this instance, but some soft compounds are not.

You will not find many Berdan primers in US apart from military ammunition, mostly the US ammunition reloading trade does not promote the Berdan system, because the primers are cheaper to produce and they can't make such a large profit. In addition many US shooting enthusiasts consider Berdan primed cases as un-reloadable anyway. However, those that take the trouble to find out about Berdan priming and reloading will be rewarded by better ignition and high shot to shot consistency.

If you are in pursuit of particular rare Berdan sizes, your best sources are South Africa and Australia, unless your quantity is high enough for you to be able to approach one of the arms contractors direct. There are also sources in Europe, but expect to place a large order in order to overcome carriage charges.

Most of the rest of this page is jottings and notes condensed down from many hundreds of messages taken from my Email inbox that have been collated and compared, so that others may benefit from what scrappy information there is on the dimensions and suppliers of Berdan primers. Names and addresses have been deleted for security reasons and to save space, but I gratefully acknowledge that many of you have contributed. If you have any further information, I will gladly add it to this page and eventually create a question and answer format so that it becomes a FAQ type of page. Much of the information about Berdan primers in old Email or Bulletin Board messages is old and out of date, which makes it difficult to rely on.

Looking for Berdan Primers, specifically size 31A.

I am trying to find Berdan primers for my 43 Spanish.

I need Berdan primers for a .360 2 1/4 nitro round. I've been told that the primer required is size 6000.

Do you have Berdan primer suppliers for 5.47 mm or .215 Swiss K-31 or Berdan primers for GP-11 Swiss (7.5 x 55) brass are .217.

Small pistol For 5.56 x 23 cartridges 4.6mm/.1800"
Small pistol For 9 x 17,9 x 18.9 x 19 cartridges 5.6mm/.1982"
Small rifle For 5.56 x 45 cartridges 5.6mm/.1982"
Large rifle For 7.62 x 39 cartridges 5.55mm/.2175"
Large rifle For 7.62 x 51; 7.62 x 54 cartridges 6.55mm/.2563"


Magtech Berdan Primer #56
The cup on the CBC/Magtech is very frail, it is for Shotshells, but not suitable for rifle pressures, even though it fits and ignites fine. With Rifle type loads it will pierce on 9 out of 10 firings.

Berdan primer No 1 10A is used in brass cased shotshells.

The PMC 5.5 mm Berdan primers are .104" tall.

I found some Berdan, large rifle primers .216, I bought one of the last remaining boxes (5000 pieces). Contact point is Diane Felsefeld PMC, Nevada phone no: 1-800-456-9182.

.303 British usually have .250" primers.

Eley Kynoch have manufactured percussion caps in types... 1A, 41, 70, 81, and No. 91 as well as numerous other numbered types, however the usage of these different numbers may not all be Berdan priming caps. Details will be added as they come to light.

Russian/Chinese/Eastern Block 7,62x54R uses a .254" primer (RWS # 6504, which is relatively shallow. The RWS 6507 is also .254", but is deeper and heavier.

European-made .303 British, and South African, is often made with .217" primers (5,5 mm) and the PMC and RWS numbers of this size are suitable.

China has made 7,62 x 54R with a .217" primer for some forty years now.

Fiocchi made .250" primers as these had been the standard Italian primer for the .303 ammunition used in their 1920s-1940s Aircraft machine guns.

Some Italian military cases use a Berdan primer of 0.204" (5.18 mm) diameter.

Old Black Powder and British Express Rifle cartridges mostly used the .254" primer, in either Copper, bronze or Brass, the Copper or bronze cup usually signifying Mercuric composition (some of these corrosive primers appear dark brown and polished).

The Kynoch and Eley .577 and .450 Martini Henry cases use the .254" primer. Modern copies of these cartridges use the .210 Large Rifle Boxer, with much detriment to firing regularity, especially in older guns with angled firing Pins, which may not strike the smaller Boxer Primer correctly, and give a misfire. The larger Berdan original primer was sure to ignite, wherever it was struck (central, side on, at the edge of the primer, etc.)

In Sniders, Trapdoors, Rolling Blocks, etc, which have angled firing Pins, the large Berdan Primer is essential for regular ignition.

Anyone have information on the Fiocchi brand Berdan primers?
I have two different batches of the 6,45 Berdan primer. One series is labeled just 6,45 and the other is labeled 645B. Does anyone have a cross reference for these to the RWS numbers? Do either of these cross reference to the RWS 6504? The documentation I have also states that the old RWS #1775 is the 6,45 and has dimensions identical to that given for RWS 6504.

The image at right was sent to me many years ago, I have lost the details of who sent it.

I need "common" No.81's not the "true British" Berdans, due to their "standard-non-standard" dimensions. (illustrated right)


Berdan Primer Dimensions by brass type
Manufacturer Calibre Headstamp Outside
Diameter
0.000" Inside
Diameter
0.000" Cup
Height
0.000" Cup
Material Note
Kynoch .303 British MK-7 K 60, K61, K68 0.250 0.205 0.109 Copper Note 1

Notes
Note 1
10 of each headstamp were measured and the average taken. There was about 0.001" variance between them all.

Berdan Primer Dimensions by primer type number
Primer Outside Cup Thickness Cup Manufacturer
Number Diameter Height Of Base Material Usage Or
mm 0.000" mm 0.000" mm 0.000" Supplier
126 6.34 0.250 2.83 0.111 0.45 0.0180 brass Note G Kynock
172 6.45 0.254 3.38 0.133 0.330 0.013 brass Note J Eley
4500 4.500 0.177 2.20 0.09 0.40 0.0157 Note A RWS
4520 4.500 0.177 2.10 0.08 0.55 0.0217 Note B RWS
4521 4.500 0.177 2.20 0.09 0.40 0.0157 Note C RWS
5005 5.00 0.197 2.20 0.09 0.40 0.0157 Note D RWS
5608 5.50 0.217 2.80 0.11 0.70 0.0276 Note E RWS
5620 5.50 0.217 2.65 0.10 0.60 0.0236 Note F RWS
6000 6.34 0.250 2.85 0.11 0.79 0.031 Note H RWS
6504 6.45 0.254 2.35 0.90 0.45 0.0177 Note I RWS
6507 6.45 0.254 3.40 0.133 0.33 0.0130 Note J RWS

Notes for number based table
Note A
Intended for use in small pistol rounds like .25 ACP, .32 ACP, .380 ACP and some 9mm calibres.

Note B
Used in small rifle rounds like .22 Hornet, .222 Remington, 5.6 and some obsolete small calibres.

Note C
Sometimes noted as 'Parabellum primer' used in 9 mm Luger (9 x 19), Steyr and majority of pistol rounds that use 4.5 mm primers.

Note D
Used in large calibre pistol rounds. Also known as 'Medium Berdan'.

Note E
Commonly used in Europe for 7.62 NATO rounds, often known as 'standard NATO'.

Note F
The most common 5.5 mm Berdan primer for rifle calibres (90% of 5.5 mm types).

Note G
Produced around 1965 and used in Kynoch production ammunition and primed cases.

Note H
Used in .303 British and related calibres, sometimes known as 'quarter inch' or Large Berdan Rifle.

Note I
For the .577 Snider, .577-.450 Martini Henry, 43 Egyptian and others. Also known as Extra Large Berdan.

Note J
Cup material 29 BWG (Birmingham Wire Gauge) RWS 6507 interchangeable with Eley 172 and used on many of the large Nitro calibres. Sometimes known as Oversize Berdan or Nitro Berdan.

Possible Suppliers at time of page compilation
The word 'possible' is used as things change over time, there is no such thing as 'certainty' in supplies of Berdan primers. Berdan primers have been manufactured by... Hirtenberger, Kynoch (IMI) (no sales of Berdan at the moment), RCBS apparently make Berdan primers in their factories and sell them to 'foreign' markets, but they do not retail them in the U.S., RWS, Sako, Sellier & Bellot (No Berdan Sales as at 2007).

BrassmanBrass.com Forbes Australia NIOA Trading

Past suppliers Not current or no longer handle Berdan
eBay no longer deal with primers, powder or loaded ammunition, but will deal in anything that is inert.

Old western Scrounger Graf & Sons eBay.com

Suppliers that I am uncertain about
Eldorado Cartridge Corporation
12801 US HWY 95 South
Boulder City, NV 89005
800-456-9182
As of Feb 2008, not handling Berdan.
SouthernAmmunition


Auction Websites
While a web page like this could not keep pace with individual auction lots, the Auction sites listed below do carry Berdan primers from time to time and should be regularly visited and searched, prices and quantities will be variable.

Gunbroker.com Auctionarms.com





Decapping (uncapping)
Spent Berdan Primed Cartridges

http://davecushman.net/berdandecap.html

There are three basic methods of removing spent Berdan Primers... The first of these is a tool produced by RCBS. I have never actually seen one of these personally, nor could I initially find instructions on how it is to be used, but I illustrate it here...



In essence it is a hardened spur that punctures the cap and hooks it out, I assume that the plain mandrel is used to hold the case whilst this operation is performed. The spur is held in place by a hexagon socket grub screw and an Allen key wrench is supplied with the kit. Since the page was first written, a kind gentleman by the name of 'Bob' has sent me a photostat of the RCBS instructions.

With all due respect to RCBS, I originally considered this device somewhat crude and likely to damage the cases. But in the light of correspondence (some of which is detailed on the instruction leaflet page I have modified my opinion to be more favourable.

The second method fills the case with hydraulic fluid (simply washing up liquid and water), stands it upright in a collar that allows for the primer to fall into a central recess. A wax covered wooden piston that is a good fit in the case mouth is then placed in the mouth of the case and sharply hit with a hammer. The resulting pulse of hydraulic pressure will remove all except hard crimped primers. I personally find this method to be as crude as the first, with risks of many types of damage to the brass. The process also showers the reloader in hydraulic fluid at every hammer blow.

Method 2a is a cross between method two and the more elegant, fully engineered hydraulic decapping system.


--------------------------------------------------------------------------------
The basic Kit
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Alternative rams
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RCBS Decapper Method
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Links are provided at left to several pages produced by R. Ted Jeo. Although the tools of the method are inexpensive to make (they were originally described by Lee W.), the decapping process is likely to be slow, with the operator getting somewhat wet, but if only a small number of cases need to be tackled, this method does the job, although I have had reports that some primers never coming out by this method. I am also sceptical about possible case neck damage or even expansion of the body of the case.

The third method is true hydraulic uncapping... It can be applied to any metallic centrefire ammunition. The process works equally well for both Boxer primed or Berdan Primed cases, but is most applicable to Berdan primers as the Boxer version is more often removed by simple mechanical means.

This third way is similar to the previous one, but removes all the objections. The hydraulic de-capping machine consists of a heavy steel container containing the same soap and water type of hydraulic fluid, with a central pillar which is drilled out to take the hydraulic de-capping bottles and hold them upright. A hole in the bottom of this pillar allows the expelled caps to exit. The hydraulic bottles have a polished steel plunger that runs in an "O" ring seal. The plunger is hit sharply with a hammer to provide the shock wave and pressure that forces out the cap.

This method of providing the pressure has several benefits...

The pressure pulse is much larger than method two, due to the use of "O" rings, and will shift hard crimped primers.

No damage to the case can occur during the de-capping process as the pressure is applied to the inside of the spent primer cup and this pressure is resisted by the case base which is itself totally supported by the annular surface within the inside of the strongly built steel bottle.

The action takes place inside the hydraulic bottle and there is little chance of the fluid squirting out to wet the operator. Sod's law dictates that the occasional squirt does happen, but it is a small price to pay for such an elegant solution to the problem of Berdan decapping.

There is a page accessible via the link at top left that describes the manufacture of a 'home made' hydraulic decapper that is also compatible with the hydraulic bottles (cylinders) that were made for use in the "Wamadet" decapping tool that was sold in the UK up until a few years ago. The drawings on that page will enable a greater understanding of the text above.

German decapping tool
Some years ago I became aware of a plier type tool of German manufacture, but I could not locate a photograph of the device, this has now been rectified as the image below has been sent by Mike Kaaland, who has given permission for publication.



To use the tool (Instructions are from translated German text and may not be accurate) position a cartridge case in the holding collar of the bottom lever, slide the locating plate into the groove of the case rim, close the middle lever to trap the case and gently enter the decapping pin into the primer cap with the top lever, then hinge upwards the top and middle lever together which withdraws the cap.


Printed from Dave Cushman's Shooting website Live CD version

411man
06-11-2008, 05:31 PM
Part 3

Boxer


Boxer Primers :


Boxer Primers

http://www.dave-cushman.net/shot/boxerprimers.html

The "Boxer" system was invented by a British army officer Edward M. Boxer around 1880, but the system is used more in the USA than UK.

The primer is the source of ignition for the rapid burning process that occurs in firearms.

The whole process starts from the percussion blow of a hammer or firing pin. The metal outer cup of the primer is distorted by this striking action causing the compression of the primer compound between the cup's inner surface and the tip of the separate "anvil".

The pocket that the primer is located in is of small volume and thus the expanding gasses and flame are forced through the web of the anvil (usually three legs) and out of the single central hole in an intense jet of flame.

As the propellant powder usually consists of regularly shaped, discs, rods or tubes, there are interstitial spaces between the particles (and in the case of tubular grains along the internal axis as well). The flame from the primer flash hole percolates through the spaces, causing immediate ignition of a large surface area of many of the propellant grains. Some powders are also porous in themselves to promote this rapid ignition.

I make no apologies for using "Imperial" dimensions in this part of the website, where they are appropriate, as metric conversion can lead to discrepancies which may become dangerous.

Dimension
0.000" Small Pistol Large Pistol Small Rifle Large Rifle
Outside Diameter 0.175 0.210 0.175 0.210
Primer Depth 0.122 3.10 mm all sizes

The principle dimensions of American Boxer primers are shown in the table. Primer pocket depth varies a little from calibre to calibre, but is always a few thousandths of an inch deeper than the primer so that the resulting primed case has its primer seated under-flush with the case head base.

The primers for shotgun cartridges are often built on the principles of the Boxer primer, but are physically larger and more robust in construction. These vary greatly in form from manufacturer to manufacturer and in the main are not interchangeable.

Removing or de-capping of spent Boxer primers is covered on the Boxer Primer Removal page.






Decapping (uncapping)
Spent Boxer Primed Cartridge cases

http://www.dave-cushman.net/shot/boxerdecap.html

Removing spent Boxer primers is usually accomplished using a small diameter pin that goes through the central flash hole, this contacts the underside of the anvil in the spent primer and pushes the primer and anvil out of the pocket. At first sight this seems a simple and obvious way of doing the job, but there are two major snags in this system...

The flash hole needs to be large to accommodate a pin that is strong enough not to bend or distort.

The underside of the anvil is uneven and can result in the contact of the pin causing side thrust and a tipping action that can wear and distort the primer pocket.

The method is very widely adopted and most die sets that are sold for reloading will incorporate such a pin in either a sizing die or a case mouth expanding die. This means that there is no extra time involved in removing the old primers as it takes place at the same time as another operation.



Cutaway drawing of an RCBS .30-06 sizing and primer removal die with the case itself cut away to show the action of the decapping pin. This set up is typical of the majority of die sets. Also shown is a second cutaway that reveals the neck expander plug (button), that works on the inside of the neck as the case is withdrawn from the die.

Some manufacturers offer a "Universal Decapping Die" that will do the job on very many different calibres. Whilst this may seem a useful item... I would recommend that decapping during the sizing operation will give the pin a greater centring effect and thus the least possible damage to the already large flash hole.

The pin in a few types of die is held in a central punch and is free floating in a loose fitting collet. This is intended to allow good self centring of the pin with least damage to the flash hole. In cases like this I recommend that the loose pin be restrained slightly with a paper or plastic collar to restrict the possible wobble on the pin without making it completely rigid. A few turns of nylon sewing cotton or PTFE plumbing tape will often do a good job here.



Hornady 'New Dimension' de-capper die stem showing collet which can be set up to give a very rigid and perfectly central decapping pin.

It is also possible to use the same hydraulic methods, that are used in Berdan primer removal, to extract Boxer primers... With a resultant lowering of primer pocket damage, but nothing can make up for the gross sizing of the flash hole.