Shotshell Trivia

[edgarspencer]

Does anyone know how the #209 primer got it's 'name'?

[OH Osthaus]

i would guess its simply a product number

[charlie cleveland]

I have never thought about the name of the 209 primer...hope to find out....charlie

[Bill Murphy]

It's the diameter of the body of the primer.

[OH Osthaus]

Originally Posted by Bill Murphy

It's the diameter of the body of the primer.

I'll go measure one-

but not in any reloading chart I have

[Dean Romig]

Drum roll please....

Take it Edgar - why were the primers called “209” ?





.

[winplumber]

Took them 209 times to make it right LOL

[J. A. EARLY]

From the interweb that Al Gore invented. Believe it or not:

Boxer primer

Meanwhile, Colonel Edward Mounier Boxer, of the Royal Arsenal, Woolwich, England was working on a primer cap design for cartridges, patenting it in England on October 13, 1866, and subsequently received a U.S. patent for his design on June 29, 1869, in U.S. Patent 91,818.

Boxer primers are similar to Berdan primers with one major difference: the location of the anvil. In a Boxer primer, the anvil is a separate stirrup piece that sits inverted in the primer cup providing sufficient resistance to the impact of the firing pin as it indents the cup and crushes the pressure-sensitive ignition compound. The primer pocket in the case head has a single flash-hole in its center. This positioning makes little or no difference to the performance of the round, but it makes fired primers vastly easier to remove for re-loading, as a single, centered rod pushed through the flash hole from the open end of the case will eject the two-piece primer from the primer cup. A new primer, anvil included, is then pressed into the case using a reloading press or hand-tool. Boxer priming is universal for US-manufactured civilian factory ammunition.

Boxer-primed ammunition is slightly more complex to manufacture, since the primer is in two parts in addition to the pressure-sensitive compound, but automated machinery producing primers by the hundreds of millions has eliminated that as a practical problem. And while the primer is one step more complex to make, the cartridge case is simpler to make, use, and reload.
Boxer primer sizes
Large (top row) and small (bottom row) pistol cartridge Boxer primers. (L–R fired, unfired, and inside view.) The tri-lobe object inside the primer is the anvil.
The same cartridge (.45 ACP shown here) can have different primer sizes depending on manufacturer.

Early primers were manufactured with various dimensions and performance. Some standardization has occurred where economies of scale benefit ammunition manufacturers. Boxer primers for the United States market come in different sizes, based on the application. The types/sizes of primers are:

0.175" (4.45 mm) diameter small pistol primers, and a thicker or stronger metal cup small rifle version for use with higher pressure loadings in weapons with heavy firing pin impact
0.209" (5.31 mm) diameter primers for shotgun shells and modern inline muzzleloaders, using a Boxer-type primer factory-assembled inside a tapered, flanged brass cup
0.210" (5.33 mm) diameter large rifle primers, and a thinner or softer metal cup large pistol version for use with lower pressure loadings in weapons with light firing pin impact. Large rifle primers are also 0.008" taller than large pistol primers.[10][11]
0.315" (8.00 mm) diameter .50 BMG primers, used for the .50 Browning Machine Gun cartridge and derivatives

[edgarspencer]

The answer lies within Jerry's excellent research. The primer in our original brass shot shell casings was .209". When we went to paper shot shells, that same primer was then case in a flanged cup. Rick's dimension drawing gives the outside dimensions, but does't show that it is actually made up of the inner, original .209" diameter primer, encased in the jacket.
I have no documentation that says the "209" was named as such, but some things are just too much of a coincidence to be otherwise.

[edgarspencer]

Originally Posted by Bill Murphy

It's the diameter of the body of the primer.

CORRECT. It's the diameter of the inner primer.