Bullet Crimp

 Decapping Pins

Decapping Center fire Cartridges

One of the steps in reloading any center fire cartridge is decapping. This is the name of the step in which the removal of the old primer occurs.  It is called decapping because many years ago primers were called primer caps.


This is one of if not the simplest single tool used in reloading but it can really cause headaches. These things tend to break at the most inopportune times.

These pins are available in quite an array of different styles and in at least two sizes and also in heavy duty.


The most common and simplest pins are just that. A simple rod.

These pins com in two sizes.
Large is about 0.080 in diameter.
Small is about 0.62 in diameter

RCBS specifies small pins for .22 to .25 caliber dies and large pins for .65mm through .45 caliber dies.

Forster specifies three sizes.

Replacement decapping pins come in three sizes. All PPC/BR dies use FDPU, standard (.080 inch flash holes) use FDPS or FDPL. All pins are packaged in five. FDPU Forster Decapping Pins (.060 inch flash holes) FDPS Forster Decapping Pins (.080 inch flash holes) FDPL Forster Decapping Pins (.080 inch flash holes).

The best practice is to have a package of large and small in your shop at all times. 


Simple decapping pin. 
Another style is the "headed" pin. RCBS specifies this pin for RCBS Reloader Special Dies, RCBS Cowboy Dies, and All RCBS "Precision" dies with the following exceptions: 6mm PPC, 7mm TCU, .35 Whelen, 357 Sig, .358 Winchester,.356 Winchester, and .416 Remington Magnum. Headed Decapping Pin 
Most manufacturers offer universal decapping dies that decap only and are used in addition, usually before the resizing die.  this is the RCBS version. Heavy Duty Decapping Pin 
This is a Lyman universal decapping pin.
Lyman Decapping Pin 
Broken Decappping Pins   
Decapping pins  can bend but they are more likely to break. This happens most often when there is an obstruction in the body of the cartridge case that prevents the pin entering the flash hole.

This also happens frequently with Berdan primed cases - since they do not have a central flash hole.

Note that the example at the bottom is one solid piece. The bent pin was bent trying to decap a Berdan primed 5.56 case.

The broken pin was broken by as rock in a 7.62x51 case.

This is significantly less frequent but I find it much more interesting than the other decapping pin problems. This is a Berdan primed case but the decapping pin did not fail.  And yes, I had to disassemble it to get it out of the shell holder.

This can also occur with a Boxer primed case with a tightly crimped primer.
Decapping Pin Piercing Case Head 
Replacing these pins is easier if you clamp the knurled end of the expander plug in a vice. It is very difficult to hold it with pliers.
























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