Small Primer Q

[Rick B]

Small primers have thinner cups than large primers. People compensate by using smaller diameter firing pin tips with the hole being bushed accordingly (typically around 0.062”). Some action makers disagree with the practice.

Does anyone know why the small primer cups are manufactured thinner than the large ones?

Thanks in advance.

 

[brickeyee]

Small primers have thinner cups than large primers. People compensate by using smaller diameter firing pin tips with the hole being bushed accordingly (typically around 0.062”). Some action makers disagree with the practice.

Does anyone know why the small primer cups are manufactured thinner than the large ones?

Thanks in advance.

Cup thickness is NOT the only way to alter primer cup strength.
An extra strike during forming will work harden the brass more.

 

[Joel]

Don't have a clue as to the why. Here are some of the numbers. https://www.accurateshooter.com/technical-articles/primers-and-pressure-analysis/

 

[K Hope]

Small primers have thinner cups than large primers. People compensate by using smaller diameter firing pin tips with the hole being bushed accordingly (typically around 0.062”). Some action makers disagree with the practice.

Does anyone know why the small primer cups are manufactured thinner than the large ones?

Thanks in advance.

Not all Primer manufacturers use the same composition mix nor do they always change the composition for a specific cartridge. (Have a look at the different MSDS’s sheets.) One reason for the thinner cup is to achieve a more reliable / consistent detonation of the Primary explosive (lead). Not all leads have the same sensitivity to impact.

Here is another good article on primers.

https://www.outdoorlife.com/cartridge-primer-technology-developments/

BR
Ken

 

[Butch Lambert]

Small primers have thinner cups than large primers. People compensate by using smaller diameter firing pin tips with the hole being bushed accordingly (typically around 0.062”). Some action makers disagree with the practice.

Does anyone know why the small primer cups are manufactured thinner than the large ones?

Thanks in advance.

Don't have a clue on primer cup thickness, but the smaller firing pins handle much more pressure. Jerry Stiller kinda pioneered this and provided scientific evidence of it.