Centrifuge marks on base of pinfire?


#1

Why would a pinfire have centrifuge marks on it?

My guess would be the machine that held it used a lot of pressure pushing it downwards while crimping it. Then had a small three-pronged piece come up from the bottom to push it loose from the machine?

What would be a guess as to the manufacturer of this?

It is a 12mm long


#2

Aaron: As I understand it, the marks aren’t associated with the priming of a rimfire cartridge case but rather with crimping the bullet. After the bullet had been inserted in a case containing the powder charge the round was rotated in a fixture that permitted a fixed knife to turn the case mouth inward to form the bullet crimp. The small marks seen on the base of the case are associated with the turning process; in later use improvements in the process made it unnecessary to actually leave marks on the base of the case. This account is taken from Barber’s excellent book on American rimfires and I hope my version of it is accurate. My impression is that the presence of the marks suggests the round was made in the U.S., but what I don’t know about pinfires would fill a thick book. Jack


#3

Aaron
What is the case length of your cartridge. The tic marks on the base are one characteristic of pinfire cartridges made by Ethan Allen. While these usually have 4 tic marks, according to Suydam’s US Cartridges and their handguns, they sometimes have three. Allen as well as CD Leet produced 12mm pinfires under Christian Sharp’s patent # 34897 between 1862 and 1870. If the case is around .767" long, it is probably an Allen made cartridge with those tic marks. The Leet and Allen cartridge cases were in between the European short and long cases, which makes then somewhat unique.


#4

[quote=“GuyHildebrand”]Aaron
What is the case length of your cartridge. The tic marks on the base are one characteristic of pinfire cartridges made by Ethan Allen. While these usually have 4 tic marks, according to Suydam’s US Cartridges and their handguns, they sometimes have three. Allen as well as CD Leet produced 12mm pinfires under Christian Sharp’s patent # 34897 between 1862 and 1870. If the case is around .767" long, it is probably an Allen made cartridge with those tic marks. The Leet and Allen cartridge cases were in between the European short and long cases, which makes then somewhat unique.[/quote]

It is right about that length.
I have another that is just a hair longer that is also no headstamp but is still shoter than the longer ones.


1.* FUSNOT * BRUXELLES - .556
2.12:rasied - .631
3. blank, 3ticks, - .769
4. blank, .774
5.H.B/PARIS:raised - .913

Short, Short-Medium, Medium, Medium, Long?


#5

One way to identify who made a U. S. produced rimfire round, aside from case marks, is to measure the diameter of the pin.
I saw a reference to this in one of Thomas’ editions of: Round Ball To Rimfire.
When I come across it again, I will post the specs. M. Rea


#6

I would think a US made round would have a pin in a standard imperial size, and a continental European one would be metric.


#7

Something that may account for the odd length of the pinfire cartridges made by Leet and Allen is that the Sharps patent called for a thick base of the cartridge to help it hold its shape after firing, reducing the possibility of the cartridge base bulging upon firing and interfering with the rotation of the revolver cylinder. This thicker base was formed by a disc of lead, which would reduce the internal capacity of the case, necessitating that the case be longer in order to hold the same amount of powder as the standard European cartridges. I would not consider sectioning one of the Leet or Allen pinfire cartridges, as they are not too common, but I would bet that the powder charge is pretty close to that of a European 12mm short pinfire.


#8

just consolidating two replies that were put in new topics…

mdrea:[quote]Pin dia. of Civil War era pinfire rounds as per Dean Thomas.
Sharps & Hankins - .068
Leet - .087
A & W - .088[/quote]
AaronN322:[quote]Anyone have the pin diameter measurements for Ethan Allen, and unheadstamped UMC?

Now I know Allen started using that slightly longer case length that was mentioned in the previous thread about identifying these. That .770 case was also used by Leet. Since these were based on the Sharp’s patent (using the thicker base with the lead disk) would it be safe to assume that S&H cartridges also used that slightly longer length?

What about A&W’s length?

Also, did UMC only make them in the standard 12mm short?
[/quote]

mdrea:[quote]Specimens from my collection show:
E. Allen .087 pin. dia., .770 c/l, ( 2 specimens )
A & W .087 pin dia., .754 c/l
S & H .068 pin dia., .745 c/l[/quote]