Original 56-56 copper case mouth wall thickness?

[El Supremo]

Hello:

Marcot provides 56-56 case dimensions that seem to indicate both variation and relatively THIN case mouth walls in the rimfire copper cases.  Modern centerfire cases average .012" wall thickness at the mouth, but I suspect the 56-56's were about half that.

It will be appreciated if anyone can please provide their measurement dimension of an ORIGINAL copper case mouth wall thickness.  Oh, and please don't dismantle an expensive relic to do this.  Thanks.

Respectfully,
El Supremo/Kevin Tinny

[Trailrider]

As Marcot shows, there was a wide variation in the outside dimensions of .56-56 copper (actually gilding metal) rimfire ammo. Unfortunately, the only original ammo I have is still assembled, and, as you state, I don't intend to take it apart. The cases had to be thin in order for the heads to be folded, incorporating the fulminate of mercury primer spun into the rims, so the rimfire firing pin could allow sufficient impact to set off the charge.

[Rim fire]

My original fired case measures .015, there may be some corrosion so between .010 and .013.

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[El Supremo]

Thanks, Rimfire:

The CW era rim-fire cases detailed in Chap. 12 of Marcot appear to have much thinner walls. Is your case CW era or maybe much later, please?  Headstamp?

By the way, a .011" - .012" mouth wall thickness is ok for a .560" body with .536" mouth ID.

Respectfully,
El Supremo/Kevin Tinny

[Rim fire]

The case was found on the East cavalry field at Gettysburg.  1863 vintage, no headstamp.

[Rim fire]

Most probably Crittenden and Tibbals manufactured.  CD Leet didn't come on line until later.

[El Supremo]

Thanks.  Appreciate the extra efforts.
El Supremo