More tiny rimfires and sub-caliber "wildcat" rimfires

Ok, MOST topics on this forum seem to be people asking questions, which is awesome, and how I am learning lots and lots…but sometimes I like to just see neat things; are you guys the same way? Or does it come off more as just a show-off, and more of the same ol’ same ol’ that everyone has already seen a million times?

I know I am a relatively new collector, and do not have NEAR as much as some of you, but I also know there are people newer than me who may enjoy seeing some things that I personally think are neat; so until people start complaining or become annoyed I will occasionally post some of what I think is neat from my collection.

Click any of these pictures for a MUCH higher resolution version

Here are a few 2mm rimfire boxes with a .22 American for size comparison.

Here is 1/2 scale .22, 2.34mm SwissMiniGun rimfire which is currently the smallest production rimfire in the world, and a long and short 2mm rimfire.

And finally, a bunch of subcaliber .22 wildcats; listing of them in order under the picture.

.10 Eichelberger LR
.12 Eichelberger LR
.14 Eichelberger LR - original Eichelberger load
.14 Eichelberger LR
.17 Eichelberger LR
.20 Eichelberger LR
.12 Eichelberger Magnum
.14 Eichelberger Magnum
.17 Eichelberger Magnum
.20 Eichelberger Magnum
.14 Eisenburgh
.14 Eisenburgh Magnum
.14 Kopp Short Case
.14 Kopp Long Case
.14 Hornet
.14-.22 OTTR
.17 Myra Minor Mite
.17 Myra Vixen
.19 BN Short
.19 Wildcat

What is the .22 American? It looks like a .22LR with an FMJ non-heeled bullet. Is that correct?

I think it is the 22 ILARCO ( aka 22 short magnum rimfire) .A 22 magnum RF shortened to 22 LR length

Falcon–Pivi is correct. The .22 American is the .22 Magnum cut down to .22 LR length. To my knowledge all the cartridges were made by Winchester. They were introduced about 1986 for a relatively short lived full-auto PDW. I had the privilege to fire the gun at the Ordnance Expo held in Los Angles in 1986. It was a nice handling weapon with practically no recoil. I think the hard to get ammo for it caused it’s demise.

Thanks for answering that. I suppose law enforcement was the intended market if it was full auto?

I am confused, the 22 ILARCO,which is very rare in my circles, is the same cartridge as the 22 American? Whis is a short version of the 22 magnum? thanks Vic


I have one lonesome example of the 22 ILARCO. They are scarce in any circle, not just yours. They are nothing more than the 22 WMR shortened. The headstamp, rim, bullet, etc are the same. Only the case length is different. The only reason the cartridge existed was because the rifle was designed as a 22 LR and the longer 22 WMR would not fit.

I have no idea where the moniker 22 American came from.


There was a previous thread on the “22 American”



While we are on rimfire wildcats here are two I posted awhile back but no luck in identifying them. Any guesses?

Four or five years age I got these two Rimfires at the St Louis Show. I purchased them from a German gentleman. Dispite the US headstamps he said they were of German origin. I don’t remember for sure but I think he said they were Police experimentals.

The first is a 5mm Remington Rimfire Magnum necked down to 17 caliber.

It has an impress “U” headstamp
Case length: 1.013" (25.72mm)
Bullet Dia: .1710" (4.36mm)
Neck Dia:.1895" (4.36mm)
Total weight: 50.88 grains (3.297 grams)
Total Lenght: 1.418" (36.00mm)
The bullet is a jacketed hollow point.

The second is based on a 22 rimfire Magnum Case.

At first I thought it was .17 cal but the bullet diameter is .1755 (4.45mm)
all the 17 cal rimfires and wildcats I known of have .1710 diameter bullets. Could it be a 4.5mm wildcat? It has a Wincherster “Super-X” headstamp.

Case length: 1.063" (26.97mm)
Bullet Dia: .1755" (4.45mm)
Neck diameter: .1960" (4.95mm)
Total Length:1.3855" (35.19mm)
Total weight: 46.48 grains (3.0123 Grams)

The bullet is a pointed full metal jacket. It has an unusual flat squared off tip and a deep groove at the case mouth crimp.

Any information on either of these would be much appreciated.


Here is a picture of two “.22 American” cartridges next to a .22 WMR, and next to a .22 LR. both .22 American cartridges have the Super X headstamp, only one appears to be a hollow point though.

Click the picture for a MUCH higher resolution version

I think it is the same as the .22 ILARCO. that round was designed for the “American-180 rimfire submachinegun”

[quote].22 ILARCO

Notes: The .22 ILARCO was designed in 1987 as an experimental round for the American-180 rimfire submachinegun. It is basically a hot-loaded .22 Long Rifle round, with the heavier bullet of the .22 Winchester Magnum Rimfire round and a strengthened .22 Long Rifle case with much more propellant. This was done to increase the power of the American-180, which could not chamber the longer .22 Winchester Magnum Rimfire round, without having to redesign the action and magazines. The power is almost the same as that of the .22 Winchester Magnum Rimfire. The .22 ILARCO round never went into large-scale production, and the sale of the American-180 patent ensured this. The .22 ILARCO is now a collector’s item.

Other Names: .22 Short Magnum Rimfire, .22 Winchester Magnum Rimfire Short

Nominal Size: 5.7x17mm

Actual Size: 5.69x15.11mm

Case Type: Straight Rimfire

Weight: 4.84 kg per box of 100; Price: $15 per box[/quote]

Is that gun you shot?

Info on the American-180 submachine gun

furthermore, the “.22 American” moniker makes a lot of sense if you look at the history of this gun and cartridge. ILARCO which stands for “Illinois Arms Company” was the company who bought American Arms, and the patent info for the American-180. They changed the rifle from using the .22LR to use the “.22SM” (this is what they referred to the cartridge as, ".22 Short Magnum.) It only makes sense that since the gun was called the American-180 it could still easily be refered to as the .22 American, or former American Arms employees who did not like being swallowed up by ILARCO did not want to refer to their creation by the new company’s name (.22 ILARCO), but rather by the one the created? (.22 American)

Aaron–Yes, that is it.

The police always seem to talk about being unable to easily stop perps who are high on various drugs with pistols in normal calibres. How effective would spraying them with FMJ .22 be?

Probably more effective than a couple of 9mm’s and at least you can be pretty sure that the .22 FMJ aren’t going to exit the body and be a danger to others.

On the whole I think that if I was shot with a burst of 20 .22 rds it’s going to make my eyes water at the very least .

at 1500 rounds a minute I would say that it is pretty effective. You would unload the whole 165 round magazine (the only size mag the ILARCO rounds came in) in 6.6 seconds.

If the rate of fire was that high then I’m sure it would be. It would also be a very cheap way of doing it if .22 LR was used.

I emailed the one company that handles the American-180 parts and accessories, etc. and asked about the ILARCO cartridge. here is their response:


The short magnum was a standard Winchester Magnum with the brass length
shortened, so that when put back together, it ended up being the same
overall length as a standard long riffle cartridge but of course a little
fatter. Their was only one run of 1M and only several hundred remain. They
were produced in bulk and to my knowledge no boxes were ever made and I am
not ready to part with any of them at this time, Sorry!

Thanks though for asking,
Val Cooper[/quote]