[waldershrek]

What is the difference between small and large pistol primers (nobody better say size)?


I though pistol primers were all the same size but I guess not. What calibers would fall into each category?

[RLDS45S]

Invest in a quality reloading manual! There are size differences. If you do not want to read the truth....but is the truth just like small and rifle primers are the same diameter, too. But, the LG rifle primer cup is taller.

[OLEDAVE]

http://ultimatereloader.com/?page_id=161

Pistol Primers

“It all starts with the primer…”

Primers are small metal cups filled with high explosive compound. The primer is stuck by the hammer or firing pin, and when struck it ignites. When the primer ignites, it shootes a high intensity flame through the flash hole (hole between primer pocket and case interior) which ignites the powder charge. Primers are typically sold in packs of 100, or bricks of 1000 (10 packs of 100).

Pistol primers side by side: 44 magnum (large pistol primer) and 357 magnum (small pistol primer)

Pistol primer parameters

There are a few basic parameters that you need to evaluate when buying primers:

1. Primer size (large, small)
   Some cartridges require a large pistol primer (45acp, 44 special, 44 magnum, …) while others require a small pistol primer (9mm, 38 special, 357 magnum, …). Depending on what cartridge you are reloading, you need to buy the proper size primer for that application.
2. Primer type (Regular, Magnum, Multi-Purpose)
   The type of primer indicates the overall intensity of the primer flame. Non-magnum loads (such as 38 special) only require a small flame to properly ignite the powder charge. Magnum loads require more activation energy since there is a lot more powder to burn. In some cases, a primer can be formulated to work with both regular and magnum loads (See WLP below).
3. Hardness
   The hardness of the primer refers to the amount of force required to ignite the primer. Some primers are softer (Federal), some are harder (CCI typically), and some fall inbetween (Winchester). If your handgun has a lightened or modified trigger/action, you may need to use softer primers.

[waldershrek]

So it looks like I need small primers for 9mm and .40......thanks guys

[WiskyT]

Originally Posted by waldershrek

So it looks like I need small primers for 9mm and .40......thanks guys

Right, just like it will tell you in a reloading manual. The load data includes primer type and is usually found after all the other stuff they want you to read. You know, the stuff that will prevent you from blowing up your gun and blaming everyone else.