Primer strength in various calibers?

Your .22 is a rimfire so it's a bit different in that the factory applies the primer compound inside the shell casing vs. centerfire calibers where the primer is a separate component assembly installed in the shell casing. There isn't a twice the powder twice the primer type of relationship and there are several different sizes of primers that are used in various center fire calibers.

Pete C.

Eric, The job of the primer is to start the fire. As the powder charge increases in volume, the primer must also become larger, but not proportionally. Small arms for instance use primers that feed flame through an orifice at the base of the case. There are two physical sizes of small arms primers. They are the same physical size for both pistol and rifle, small and large. The case size dictates the physical primer size, but there are some wildcat exceptions. So you have small and large pistol, small and large rifle and in both pistol and rifle there are magnum primers, also in small and large. Large caliber munitions, 50 Cal and above, use primer tubes that screw into the base of the case. These primer tubes have a similar ignition cap on the outside, but they also have a very fast pistol type powder in the tube that the cap ignites first. When the primer charge ignites, the tube blows out in a predictable manner through precut slits in the tube or a series of flame holes drilled in the tube and then taped over with a cellophane tape, which ignites the main charge. This is actually an exact science because these ignition systems must start an adequate, consistent and common flame front in the main charge. If , for instance, two or more separate flame fronts were inadvertently started at the same time, the collision of the independent flame fronts would cause a very rapid rise in pressure in the shell, which then sends the main charge from a rapid burn mode to explosion mode. This is called detonation and the phenomena is exactly the same as in an automobile engine except much more violent. Steve

"Eric R Snow" wrote in message news: snipped-for-privacy@4ax.com...

No. Once the fire is started..it self sustaining until all the powder is consumed.

Only on large cases with hard to start powders are more powerful (magnum) primers used.

Gunner

In small arms...this is known as a Kaboom.

Gunner

Thanks Steve. A nice informatine answer. Eric

Some good info (in addition to Steve Lusardi's excellent post) at

that there are also special military "hard" primers to minimize slam-fires in some military pieces.

Caliber and cartridge determines primer size (large or small) and choice between pistol or rifle. Choice between regular and magnum generally depends more on choice of powder: some magnum charges require more ignition. This has more to do with burn rate and powder configuration (rod vs flake or ball) than amount of powder used. It's best to stick with (or only vary slightly from) proven recipes, which include choice of primer. For example, there are powders (e.g. W291) that can produce unsafe pressures at LESS than recommended load because they may detonate rather than burn briskly.

Eric R Snow wrote: When using larger caliber rounds with larger

Yes, there are 8 quantum leaps in primer strength for hand held guns:

Depends on the caliber. An 8" howitzer uses a 30-06 blank as the primer.

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According to Eric R Snow :

Well ... from my own reloading:

1) There are two sizes of primers (excluding Berdan) -- large and small. 2) There are two groupings within those sizes -- pistol and rifle. (Rifle has a harder metal cup to resist higher pressures so it is less likely to perforate. The hammer and/or firing pin in a rifle has more mass and a pistol is not likely to reliably fire a rifle primer.

So far, this says nothing about the actual strength of the primers. (Though there may be more oomph to the rifle primers.) I'm also skipping the top-hat primers used with cap-and-ball weapons, as they are not used in modern production equipment. However ...

3) There are regular and magnum primers. The magnums put out more flame for a given size.

Obviously, if you let Berdan primers into the game there are other things about which I know nothing.

Enjoy, DoN.

Thanks for the info Don. I just get curious about things and RCM seems to always come through. Even for the more esoteric questions. Eric

And now I wonder if the original BB caps had an extra dab of primer. As stated in the article I finally quoted,

only used primer to shoot the lead, and these were used in shooting galleries. We used to use them to shoot rats in my cousin's pigeon coop at night. I think most everyone had a box of them around to dispatch pesky rodents and birds when they didn't want a loud sound or the bullet to travel very far.

Steve