Not to argue with Oleg Volk, a fine source of information in his own right - - - - His information above is no doubt correct as to earlier shoulder arms. I read somewhere that Kolibri means "butterfly" in some European language, so, a tiny cartridge might well be so described, or named.
From the Book of Pistols and Revolvers, by W. H. B. Smith, 1948, updated by Joseph E. Smith, 1968. 7th ed. P. 53--
KOLIBRI Auto and Single Shot, 2.7 mm and 3mm. This reference is to the 3mm.
These cartridges are in every way true miniatures--the cartridge case is of brass, a center fire primer is used, and the bullet is a lead core surrounded by a metal jacket. The bullet weighs about 5.3 grains, the powder charge about 1-1/2 grains.
This cartridge was developed for the Kolibri Automatic Pistol--a miniature blowback pistol functioning on the same basic principle as the regular pocket automatics of standard caliber. It may also me used in the Kolibri Single Shot Pistol, a hinged-frame tip down barrel arm.
While these arms are in no sense practical weapons, it must be noted since there are rather large numbers of them in existence that at close quarters they will penetrate as much as 1-1/2 inches of pine; and when it is remembered that a penetration of ½ inch in pine is equivalent to a dangerous flesh wound, it is at once apparent that they must be handled with due care.
The book illustrates both the auto (rather like a Browning 1900 pistol without trigger guard) and single shot, a cartridge box, and a 3mm cartridge with a .22 LR for comparison. The whole 3 mm round is well shorter than just the .22 LR case, and, if the .22 is 5.56 mm bullet, the diameter is just over half. It looks like a scaled-down .25 ACP, not a giant in itself.
HOLD THE PRESSES--Just found more information. This from Cartridges of the World, 4th Edition, by Frank C. Barnes, c. 1980, pg. 159. There is a good illustration of the 2.7, with magazine out. Looks to have a 8 + 1 capacity. He lists information, estimated only, for both cartridges, 2.7 and 3 mm. I think he over estimates the weight of the 3 mm, at 12 to 15 gr. He says the guns and ammo were introduced around 1914. The 2.7 mm (.105 to .108"), with a 3 grain bullet and estimated velocity of 650 to 700 fps, would develop a blistering three (yes, 3) foot pounds energy, compared to the .25 ACP with 73 fpe. He concludes,
The 2.7 Kolibri could not be considered a humane caliber for hunting anything. However, it might do to dispatch a trapped mouse or eliminate an overly aggressive cockroach. It is not practical to try and reload these small cartridges.
Redundantly,
RR
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---The Second Amendment ensures the rest of the Bill of Rights---
[This message has been edited by Rocky Road (edited August 06, 2000).]
[This message has been edited by Rocky Road (edited August 06, 2000).]