9.8mm Colt?


Whilst at the ECRA meeting at Bisley on Saturday I found this in a .50p junk box marked as a.38ACP, which it obviously is not.

It is unheadstamped apart from the “W” on the primer and from the dimensions appears to be a 9.8mm Colt.

Dimensions are

Bullet .381
Neck .404
Head .406
Rim .402
Length .911

Is this an early Winchester run of 9.8mm? Are these common?



I am not sure what happened to the second image, but here it is.




Nice find there! I believe the unheadstamped variety pre-dates the headstamped type. Don’t know about its availability in Bisley, but I would say the headstamped variety is more often seen around here. There is also a “W” stamped in the projectile of mine (with a headstamp) if I recall correctly.



The 9.8 mm Colt is an interesting round, in my own opinion primarily because the cartridges are so often encountered, sometimes in quantity with the headstamped version (full boxes, multiple loose specimens, etc), considering that the pistol for this ammunition was never serially produced. .

The project seems to date from mid-1908 and went on until at least 1913. The known box labels for the headstamped version of the cartridge (W.R.A.Co. 9.8m/m A.C.) all have a date of 8-11 (August 1911). It should be noted that this is the date of the acceptance of the label design and does not date the contents of the boxes.

The Colt Pistol was given the designation of Model 1910 and has also been seen referred to as the Model 1910-1911 in Colt records. Various factory records of gauges for this pistol date as late as October 1913. Factory records would indicate only a few pistols were made. There are references to a Serial Number “0” (Zero) and a Serial Number 2. The pistol itself is very similar to the 1911 Colt, but is about 10% smaller in most dimensions. Coincidental to the October 1911 acceptance date of the ammunition box label is that Eugene Reising, of Reising SMG fame, picked up a sample of the down-sized pistol at the Colt factory in late September or October of 1911, and took it to Europe for a trial held in Bucharest, Romania. The metric designation given the cartridge probably is evidence that the whole project was aimed at European sales. The gun was also shown in Bulgaria and Serbia, but the timing was very inopportune. With WWI on the horizon or already in progress, no country had much interest in starting production of a whole new pistol. With the lack of interest in the gun, even though it performed well in the trials, Colt lost interest in the project, and never followed through with it after WWI. It is a shame - what a pistol it would be even today chambered in 9 mm Para and .40 S&W!

The unheadstamped cartridges, loaded with a 150-grain flat-base bullet, were evidently made in several variations, but the only one commonly found today is the one that opened this thread. I have this round in my collection with two different sizes of “W” on the size 1-1/2 copper primer, and while of no significance except to a collector, even that is rare. The unheadstamped cartridges were the first variation.

Headstamped rounds are found only in one variation normally, although a few fortunate collectors have factory dummy specimens, with a wood spacer and a small hole in the case. These are normally found, if at all, with a blackened case. Another dummy, even rarer, is simply an inert assembly - that is, a bullet in an umprimed empty case. A tinned-dummy proof loaded, a well-worn specimen, is reported by Dan Shuey. All of the headstamped rounds are loaded with a 130 grain FMJ bullet, with a small “W” stamped in the side (the projectile of the unheadstamped rounds do not have the “W”). The 130 grain bullet appears to be the same length as the 150 grain bullet. The weight difference is probably the result of the recessed base of the 130 grain projectile. The headstamped rounds have a primer developed at the time and perhaps specifically for this cartridge, the No. 13, which had a non-fulminate mixture and a flat-brass cup.

Both types have what some call a case cannelure, but like many early auto pistol rounds, it is actually an internal shelf, or shoulder, that the edge of the bullet’s base rests on keeping it from pushing back into the case upon feeding. A measured specimen shows a case diameter of 0.4035" above this internal shoulder, and a reduced diameter of 0.4005" below it.

The unheadstamped rounds, as would be expected, are considerably scarcer today than are the headstamped specimens.

Notes from my own observations, Woodin Laboratory, and the well-known expert and author on all things WRACO, Dan Shuey, were used in this reply.



Great info! Thanks for posting that. I should just be quiet and let the experts do their thing…

Was there a European version of this same cartridge (9.65mm?) or am I thinking of something different? Regardless, a 9/10ths scale Mod. 1911 would be pretty sweet in the mid bore calibers.



Dave - Don’t do that. Your postings are just as important to this Forum as anyone else’s!

You are absolutely correct about a European version, called the 9.65 x 23 mm Browning. It was for the Browning Model 1910, also called the “Grand Browning,” which is pretty much the same as the Model 1911 Colt. The first Grand Brownings were in .45 Caliber, but in 1914 FN produced a few in the 9.65 mm Caliber. The German invasion of Belgium in the same year was probably responsible for the cessation of production of the model, although it was shown again at a French Trials c.1922. It went nowhere past that.

The cartridge is basically the same as the 9.8 Colt, with dimensions of known specimens falling in the same ranges as those of the Colt/Winchester Cartridge, and the case length being basically identical. The bullet weight was approximately 115 grains, according to Erlmeier and Brandt’s "Manual of Pistol and Revolver Cartridges, Volume I. The projectile was what I would call semi-turncated, that is, the same general pattern as the well-known German Truncated 9 mm bullets, but with the shoulder and the point more rounded. Erlmeier and Brandt actually give UMC credit, saying it was based on their designs. I don’t know if that is correct. The cartridge they would have to be speaking of was the .41 Colt Automatic, not the 9.8 mm Colt. With the dimensions being closer to the latter than to the .41 Colt Auto. However, the .41 Colt Auto is still very similar to the 9.8 mm Colt. My bet would be, though, unless there is documentation that I have not seen (highly likely - I have seen little original FN documentation on anything), that the 9.65 was based on the 9.8 mm by Winchester. All known examples of the 9.65 mm are headstamped F N *.

Reference: Erlmeier and Brandt as cited in text
Reference: The Belgian Browning Pistols 1889-1949, by Anthony Vanderlinden


Mr Moss…you are unbelievable

Can we “download” your brain…the “cartridge part” anyway (and your referecne files!!!) and add a dedicated wing to the IAA Library ?

I like reading your posts about things I don’t give two hoots about !
(unless you were to paint a tip on the bullet!)




More great information. Thank you!

Here are pics to show the headstamped and more common version with no “W” on the primer, but sporting one on the projectile.

If loaded to full potential, that 9.65x23mm must have had some impressive velocity with a 115gr. bullet. I’ve never seen anything but “guesstimate” velocities for the 9.8mm AC.



Dave - I’m sorry. My box label for the 9.8, the headstamped version with 130 grain bullet, gives a velocity of 1200 FPS. Sorry I forgot that. My label is just that - I don’t have the box, regretably. All I have is the file card for the box from the old H. P. White Laboratory collection.
They only save parts of the label that were different. For example, if the two end tabs said the identical things, they only kept one on the card.

I would suspect that the 150 grain bullet, with its smaller powder charge and heavier bullet, probably was in the 850 to 950 FPS range, but that is only an estimate on my part. I have no documentation for that.

I have no published data for the 9.65 Browning, but suspect it was in similar ranges. If the bullet weight in Erlemeier-Brandt is correctly given at about 115 grains, it could have had a velocity of 1300 FPS or perhaps just a little higher. That would be a hot load for the times, but I am sure the Browning-designed, FN-made Grand Browning Pistol was up to it.


Great info, John. Yet more IAA posts to copy and paste into my files!


Thank you John and others for your usual erudite and informative answers.

However, one has to wonder how an early Winchester round got to the UK. I do not know of any British trials of this pistol or round but I will check. Then I can call it part of my British military collection!

Otherwise it is up for grabs.



TonyE - In trying to condense the material I have on the 9.8 Colt, much of the story was left out. In fact, I probably over-stated one cause for the lack of market success for the 9.8 mm. More on that in a minute.

Tony, your 9.8 mm cartridge could, have course, simply been acquired in trade by a British collector from an American and ended up eventually where you got it. It would be much more fun to assume that it came there in Late 1911 with Reising! Actually, the English Pistol Trials at Enfield in late September of 1911 were the first stop for Charles L. F. Robinson, Vice President of Colt and responsible for Colt’s effort to halt a marketing war with FN, and Eugene Reising, on their European trip that took them to Romania, Serbia, Bulgaria, etc. Along with one of the down-sized 9.8s, they had a "Model of 1911 Special Army .45 Pistol, serial number 10, with them, probably for those trials. You may want to start your research there, and I surely would love copies of anything you find. I will quote an article from the June 1988 issue of American Rifleman magazine, “Colt’s Baby Model 1911,” by William H. D. Goddard, pages 26-29:

 "On Oct. 19, Chiarman Skinner read a cable from Robinson for Colt's board.  It told first of the Colt's successes in London and Bucharest, and second, gave mention of the specifics of a proposed new FN non-competition contract whereby the Belgians would "withdraw from Mexico and Central America if Colt would keep out of the Balkan States.""

This quote goes to the heart of your question - Reising and his “Baby Colt” were in England before going on to Bucharest, and he had a supply of 9.8 mm Colt ammunition with him. A few rounds may have been passed out to “notables” with an interest in it, as souvenirs, if for no other reasons. More fun to think of your round actually being one coming from the hand of Mr. Eugene Reising.

At the same time, it makes my statements regarding the bellicose situation in Europe having some effect on the sales of Colt’s new pistol, while a possiblity, a weak one at that and secondary to the long-ongoing competative conflicts between Fabrique Nationale d’Armes de Guerre, Herstal, and the Colt Patent Firearms Manufacturing Company of Hartford, primarily concerning the work of John Browning. That story is too long to tell here, but probably the agreement referred to was much more important than the looming conflict in Europe. in the Colts Pistol not being adopted in Romania, where it did very well in the trials. In trying to condense material for my answer, which Lord knows are often too long to the point of boredom anyway, I did not mention the trade in-fighting between Colt and FN and over-stated the situation in Europe as a cause of the Colt going nowhere.

Also, in revisiting my files and putting some facts together, I have found mention of 9.8 mm pistols from serial number 0 to serial number 3, inclusive. Within that numerical grouping, all numbers were found mentioned in one context or another.The whereabouts of all four are not known today. One is known in the collection of the Springfield Armory National Historical Site, apparently a pistol assembled from parts and possibly the one that was in the Kirby collection, in Texas. Serial Number 3 is also known, but I don’t know where it is today. Further, in my mention of one gun returning to the scene being sent to a French trials in 1922, I found in more closely examining the material I have at hand, a conflict in that information. The gun going to the French trials was an FN pistol, while The American Rifleman article by Goddard indicates that in 1922, Pistol No. 2 was booked out of the Model Room to H. S. Campbell, one of Colt’s South American Salesman. Whether he took it for his own reasons, for showing in his normal Hispanic territory, or actually took it to France for a trials, I cannot answer. It is obvious, and should have been to me, that this is a Colt pistol, and has nothing at all to do with the French trials.

Sorry if I muddied the waters in my attempts at brevity in my initial answer. With many of these subjects, there seems always more than one story to tell, and sometimes in making a fairly quick answer, I read my files only as “deep” as it requires to give a response. A bad habit on my part, but necessary to time constraints.

Edited for spelling correction only.


Thank you John for that very useful summary of the connection with the 9.8mm and the UK. It gives me something to start on next rtime I am at the Royal Armouries library (which incorporates the old Pattern Room library).I will probably be there some time before Christmas looking for something else, but as ever, it is easy to get sidetracked!

I shall be down at Bill’s for Thanksgiving so hopefully I shall have some time just after that.

I have a copy of the British trial of the .38 Colt from 1903 but nothinmg later.



I doubt it was a coincidence that the 9.8mm Colt’s body diameter matched that of the .41 Long Colt cases, nor that the 9.8mm’s case rim duplicates that of the .38 ACP.

Photos of the Colt pistol can be seen in Donald Bady’s book “Colt Automatic Pistols”, and the FN 9.65mm pistol can be seen in Blake Stevens’ book “The Browning High Power Pistol”.


The 9.8 Colt and the .41 Colt seem to be contemporariies. There are great similarities. The rim size of a .38 Colt Auto round contemporary in manufacture to the 9.8 in my collection had similar rim diameters of .4014" and .4025" respectively, basically the same for all practical purposes.

The base diameter of the 9.8 Colt and .41 Colt Auto in my collection are identical ar .404". The .41 Colt Auto (case only) I have has a larger rim than the 9.8 running from .418" to .420" depending on where measured. The overall case length of the .41 at .8925" is only slightly shorter than the .38 ACP, at approximately .8925" (I always have a little difficulty measuring case length of a loaded, bulleted round). My unheadstamped 9.8 specimen has a case length of approximately .913".

As to Dan’s comments, I would think that Colt gave Winchester and Remington some general measurement spreads that they thought the cartridge should fall into. Why the two names, 9.8 mm Colt and .41 Colt Auto, for two rounds so similar, is unknown to me. I still feel that the 9.8 was given a metric designation to appeal to the European market, the only market place it was formally shwon in, to my knowledge. I don’t know what happened with the .41 Colt - I have never seen a loaded round, although I assume they exist.

I was told once that my case was an “H.P. White Reproduction” to give them a specimen. I acquired it as a factory case, but that could be possible. I would think that if H.P. White had made up a few cases for their own purposes they would be turned brass - my case appears to be drawn. It does not have the usual “lathe turning marks” associated with that type of replica case. I mention this only to qualify the measurements. If a replica from H. P. White Lab, it might not precisely meet UMC specifications.

Despite the fact that the Colt pistol was reduced in almost every dimension by 10% from a Government Model (1911), I am sure Colt would have liked to keep some commonality of measurements with established cartridges. Blowing out the case body of the .38 ACP to the tim size seems like simply a logical way to make the .38 into a 9.8 mm (a true .38 instead of a true .36).


Didn’t the .41 Colt Auto date back earlier than the .45 ACP? I want to say that the prototype was based on the “parallel ruler” M1900/M1902 type. There has been speculation as to why the semi-rim was used for the early ACP cartridges. One theory is someone thought that semi-rims gave more positive headspacing. The other is that someone desired to have cartridges that could be interchanged between semi-auto pistols and revolvers.


Daniel: Since the semi-rim feature was also part of the cartridges for the Winchester family of blowback-operated semi-auto rifles designed in this same period I’d think the belief in superior headspacing was involved rather than auto pistol-revolver interchangeability. Jack


Yes, the .41 Colt dates from March 1903, according to UMC’s records. They commenced making samples for Colt that month and year, that are noted as “headless shells with the same length as the .38 Automatic, and using a loading of 6.5 grains of Walsrode Shotgun powder with a 150 grain FMJ bullet.” Bullet diameter was to be .386 diameter, with the cartridge the same length as the .38 Automatic. Head diameter was to be .417 to .422". I assume the head diameter is (under correct diameter since the head is really the rim and not the base) the rim, since my own specimen measures right within those specifications.

I consider “contemporary” to be the same general era betwen compared items. I guess some define it as made at exactly the same time. Both the .41 Colt and the 9.8 Colt were “born” within the first nine years of the 20th Century, about 5 years apart. Perhaps with that spread, “contemporary” was a poor choice of words on my part, although its the way I think of the word.

Edited to remove typographical errors only.

The .45 ACP, or UMC’s part in it, dates from February 1904, so yes, the .41 Colt was earlier than the .45 by a little less than a year.


I’m sure you’ve all seen this box…

Grand Browning 9.65mm pistol