Anyone have any pictures of some really small rimfires?

I would like to see some pictures of rimfire cartridges smaller than a .22.
It would be awesome to see these all lined up, but I don’t know if someone has all of these.
Here are the calibers I know of:
.11 Whatzit
4mm Flobert
4mm Long Flobert
4 x 14.5 Swiss
4.5mm Interdynamics
.14 Alton Jones

Anyone know of anything else?
I have the 2mm short and long, 4mm flobert short and long and the .14 alton jones.

Here is a schematic drawing of the 4.5mm Interdynamics:

There are also the various .17’s and the 5 mm Remington magnum

I have some stuff on the 4.5x26R Interdynamic, thanks to George Kellgren, who invented the thing back then and now is a master-mind of the US-based Kel-Tec company

Well, there’s the 2.34mm Swiss Mini Gun (with a 22LF and a 18mm Swiss)

If you like 'cats, here’s a few


4.25mm Lilliput, 2.7mm Kolibri, .11" Whatzit, 2mm Rimfire, 1.5mm Pinfire


.10, .12, .14, 17, .19, .20 Eichelberger Rimfires (.223 behind for scale)

Here are some more.


.14 Kopp Short, .14 Kopp Long, .14 Hornet, .14 Eisenburgh Magnum (note; NOT Eichelberger), .14 Eisenburgh (note; NOT Eichelberger), .19 BN Short, .12 Eichelberger Magnum, .14 Eichelberger Magnum, .17 Eichelberger Magnum, .20 Eichelberger Magnum, .17 Myra Minor Mite and .17 Myra Vixen.

…and the one I nearly missed, .14 OTTR.

Here are some experimentals from FN related to the P90 project.

The first two are 4x27R, the next is a 4.5x27R and the last 2 are .22 Magnum cases - triplex and APDS loads.



What are the headstamps for the P90 project rounds?
Also what is the exact diameter of the 4.5x27R bullet? Is the bullet FMJ with a flat point?



Those are some pretty crazy looking bullets on those!

I think I am beginning to really like wildcats!

Rimfire Paul - the headstamps on these rounds are (from left to right):

Super-X monogram
Super-X monogram
F (bullet diameter is 4.47mm). It is a FMJ, GMCS. The meplat has a slight radius.
Super-X monogram
Super-X monogram

There are several more variations that I could illustrate, but there are questions surrounding their authenticity.

AaronN322 - the rounds I have pictured are not wildcats. They are military experimental (if you accept that a wildcat is what one private reloader makes and that a military experimental is from an official program).


Paul - there is no current 5.7x28 to compare for scale in the photo, but am I right in assuming that the ones shown above are all a bit smaller than current 5.7x28 cartridges?

Hi DK - yes, these are all smaller than the 5.7x28 P90. Here’s another picture with an early 5.7 x 28 in the centre (5.7x28 FN 88; with the early ogival projectile). The rounds on the right are described above. The rounds on the left are as follows:

5.7 x 23R - Headstamp is 'C’
5.7 x 27R - Headstamp is Super-X monogram
5.7/4.5 x 27R - Headstamp is ‘C’


I believe that .11 Whatzit would be considered a centerfire if it was a true cartridge, since the case is a No 4 Winchester shotshell primer.

Why the distinction? If a wildcat cartridge is one derived from an existing case, why wouldn’t it be considered a wildcat regardless of whether the developer was a private individual, commercial company, or military arsenal?

Very interesting pics of the rimfire precursors to the FN 5.7x28 round, BTW. Thanks for sharing.

Not necessarily as uncommon as the rest posted, but here is what I have so far.

.2mm blank, .2mm ball, .11 Whatzit, 4mm short, 4mm long, .14 Alton Jones, .17 Mach 2, .22 SSS, 6mm short, 6mm long, 7mm

Now, I have a question, the 7 “flobert” rounds pictured, don’t they have less powder in them? or only the primer charge or something like that?

A couple new ones.

You guys have any info about the two to the left of the .14 alton jones?

The one directly to the left of the alton jones has the <> western stamp on it. Supposedly these were made from fired .22s during WW2 era. The one to the left of it appears similar to the .11 Whatzit, but there is no headstamp. What kind of bullet is in it?

Bigger version: