.351 Winchester Aircraft Cartridge

This scan was taken out of Stebbins, Henry M. “How to Select And Use Your Big Game Rifle” Washington, D.C.: Combat Forces Press, 1952.

Does anyone have one of these cartridges in their collection, and if so, can you post a photo, including headstamp? Mostly I’m curious as to whether this particular loading was a US commercial contract, or the French-produced “ART. W. 351” loading as referenced to at municion.org (www.municion.org/351wsl/351wsl.htm)

I realize this might have been covered in a past IAA journal issue judging by the index, but I’m unwilling to purchase the archive for only a handful of articles. My particular interests in cartridge collecting are in the .32, .35, .351, and .401 Winchester Self Loading rifle cartridges.

Thanks in advance for any help!

That is a very interesting round. I think it may be a US made item as I have not seen a similar round of European manufacture. All the French made .351 and .401 Winchester rounds I have seen had the normal profile bullet.

As you probably know, as well as the French the British RFC used the .351 and also experimented with the .401, but again the rounds used the normal profile bullet.

Churchill (the gunmaker, not the politician) badly injured his eye whilst trying various tracer compositions in a .351, but these were made by drilling out a tracer cavity in normal ball bullets.

I have a Kynoch made .351 proof round from a packet dated 1915 that I believe was used to proof the British military M1907s.

It will be interesting to see if anybody can add any further information.


Are you sure it is not an us exp ctge ?

I think J-P is right on. That cartridge looks like the Winchester .345 Machine rifle cartridge. Between known specimens and scant Winchester records on the subject, six variants of the cartridge have come to light, and are described on pages 285 and 286 of the original edition of HWS Volume I.

The round had a special straight rimless case, measuring about 1.375". Other dimensions were:

Rim: .372"
Head: .375"
Neck: .375"
Bullet Diameter: .348"
Overall Legnth: 1.897" - 2.081" depending on the projectile.

It was designed during the WWI period. The weapon was designed for air use but had an alternate barrel with a bayonet lug for ground use. It was a Winchester internal project and evidently never tested by the government.

Of course, just going by a picture, with perhaps a wrong caption for this cartridge, it is difficult to be sure. I am not aware of a 351 Winchester with this bullet shape, but I don’t collect them and certainly am not expert in that field, by any stretch of the imagination.

Edited for spelling only.

Thanks John, it did not occur to me to look in HWS, as the .345 is not a round we see a lot of in the UK!!

Returning to my previous post, here is the label for the .351 proof rounds. The charge is 13 grns of “Revolver Cordite”


It is interesting that Stebbins would list this experimental .351 load as an option for hunting deer, as if the hunter could find a box of these at his local gun shop, stacked on the ammo shelf between the .35 WSLs and the .38-40s. I’d gladly take a box or two.

Thanks for all the replies, I believe Stebbins included this cartridge in the illustration merely as a curiosity that was perhaps on hand in his collection.

I agree with the conclusion here- probably a .345 Winchester Machine Rifle cartridge. Does anyone know the headstamp of the .345 WMR cartridge? Were these just special loadings of the .351 Winchester SL cartridge case? Probably quite a rarity if it has a unique headstamp, otherwise I would estimate it’s an easy one to reproduce. (.345" is the bore diameter of the standard .351 Winchester SL chambering- likely they used the same case). Similarily, if Stebbins only had a cartridge with the .351 SL headstamp and some provenance as an aircraft rifle cartridge, it’s easy to see him skipping over listing the cartridge in the caption as the .345 WMR.

According to my copy of ARMAX’s Vol. III, No. 1, 1990 article on “Winchester Centerfire Rifles” by Konrad F. Schreier, the Winchester Machine Rifle was developed in 1916, tested by Springfield Armory, but dropped from further work. It was intended for aircraft or ground use judging from two different barrels included with the prototype rifle. The photo included of the .345 WMR is very similar to the photo in Stebbins’ book.

Thanks for the scan of the Kynoch cordite proof loads. If anyone has further information to contribute, I am very much interested in the WWI cartridge loadings and use of the Winchester self-loading rifles.

HWS Volume I shows that the Wincheste rammunition was made between February 21 and August 14, 1917. I don’t know exactly what that does to the 1916 date fromKonrad Schrier’s work on the subject. I simply don’t know enough about the project to know if there was pre-1917 development of the weapon in a different caliber - perhaps the normal .351, or what. WHS cannot confirm that the rifle was ever tested by Springfield. I am not saying it wasn’t, and actually, HWS Volume I really leaves it open as well: “This was a Winchester internal project, and although no record has been found of its being tested by the Ordnance Department is is mentioned here because of its obvious military intention.” I think the operative words there are “no record has been found.” I have not seen Konrad’s work on this project, so don’t know if he documents the 1916 date or Springfield’s involvement with the project or not. Without documentation, it is all a guess and a gosh, of course.

Most of the specimens noted in HWS did not have a headstamp. For some it is not noted either way. One black-cased dummy with an empty, blind (no flash holes) primer pocket is reported with a headstamp of W.R.A CO. .351 S.L. Uncharacteristic with JHWS, another specimen is described as “headstamp w and w on primer” which is somewhat confusing, especially in the case of a lower-case “W” being used in the description. Just from the text, one must assume that the headstamp was simply a small “W” and nothing else on one specimen described. I don’t know if this is correct or not, or if more of the sentence was dropped somehow in the printing.

All my reference is from the 1st edition of HWS.

A couple of pictures to accompany the text…the round on the right has a ‘W’ only on the primer. The round on the left has a blind primer pocket. Note the difference in the extractor groove profiles.

In Dan Shuey’s comprehensive WRA Co Headstamped Cartridges and Their Variations, Volume 1, page 245, he illustrates a picture of the gun.