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-   -   Centerfire and rim fire (http://www.firearmstalk.com/forums/f30/centerfire-rim-fire-94794/)

Gunslingerbarred 08-01-2013 09:23 AM

Centerfire and rim fire
 
Can someone please explain the difference to me, what is rim fire and what is center fire?

mountainman13 08-01-2013 09:25 AM

1 Attachment(s)
Picture worth a thousand words...

austin92 08-01-2013 09:50 AM

Aside from the picture above explaining it all, rimfire will be your .22lr, .22wmr, and .17hmr. Common centerfire rifle cartridges would be .223 Remington, .308 Winchester, and 30-06 Springfield. Rimfires are not reloadable where centerfires are. Google/Wikipedia are your friend :)

c3shooter 08-01-2013 09:55 AM

Good pics. In rimfire, the rim is folded over to form a channel, and priming compound is put in the channel. On firing, the firing pin strikes the rim, pinching it, causing priming compound to explode. One of the first complete metallic cartridge was a rimfire.

Centerfire- priming compound goes into a small metal cup, placed at center of case head. Firing pin crushes priming material between the cup and a fixed anvil, making it explode.

And not to confuse you, but back in the mid 1800s, there were other priming systems- pinfire, lipfire, cupfire, Crispins, etc. They did not work out, and fell by the wayside.

cblowe13 08-01-2013 10:01 AM

So why can't rim fires be reloaded?

clr8ter 08-01-2013 10:24 AM

You've already put a crush in the rim, which you can't fix, and how are you supposed to get the primer into the rim again? With reloadable center fires, (there is non-reloadable centerfire, too), the primer is a self contained unit, press out the old one, press in the new one, and reload.

hiwall 08-01-2013 01:36 PM

Rimfires(larger calibers) have been reloaded in the past with mixed results. Wet priming compound is put in the case and then the case is spun to get the "primer" into the rim. A large rimfire case can be reloaded 2 or 3 times. Obviously sometimes the case must be turned to expose a "new" section of the rim to the firing pin. This is more difficult sometimes as some guns have dual firing pins(hit the rim in two spots at once).

bigjim 08-05-2013 03:39 AM

They can be reloaded, it is just too difficult and time consuming. You need to mix and apply your own primmer compound, apply and let it sit and dry. (very small amount) Then powder and bullet, crimp and you are done.

Jim

I don't remember seeing load data for 22 LR in any of the books, but I am sure it can be found.

c3shooter 08-05-2013 12:03 PM

Quote:

I don't remember seeing load data for 22 LR in any of the books, but I am sure it can be found.

And you are not going to find it in a loading manual, for a couple of reasons-
1. No heel seated .22 bullets available
2. Powder used in .22 rimfires not for sale
3. Making priming compound is not only incredibly dangerous (says the guy with a Master Explosives Engineer's license) but unless you have a license to manufacture explosives, also incredibly illegal.

There ARE some kits that have a heavy, reusable brass case with a replaceable primer to allow shooting of older rimfire rifles (like the .41 Swiss, .56 Spencer, etc)

TekGreg 08-05-2013 12:44 PM

Modern cartridges use rimfire priming for rounds so small that a removable primer would be impractical, i.e. .17, .22, .22 mag. The smallest centerfire primer would provide too much ignition for the small amount of powder in these smaller cartridges. The diminutive size also doesn't allow reloaders to experiment with different powders and loads. Even the smallest centerfire cartridges that can be reloaded, like the .25 and .32, are not popular to reload due to inability to improve performance.


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