Prototype Winchester Commercial Rounds


At SLICS, I picked up an interesting series of prototype Winchester commercial rounds.

.458 (SUPER SPEED 300 H&H MAG)
.458 (no headstamp)
.412 Winchester dummy (SUPER SPEED 375 H&H MAG)
.408 Winchester – dummy and ball (no headstamps)
.338 Winchester Mag (no headstamp)
.356 Winchester (W-W SUPER 308 WIN)
.307 Winchester (no headstamp)
.307 Winchester (W-W SUPER 308 WIN)
.308 ‘Fat case’ (no headstamp)
.30-80 Winchester (forerunner of .308 Winchester – no headstamp)
.284 Winchester – (+) WRA 61 headstamp
.22 Winchester. Case length is 1.90” (5.6 x 48mm) (no headstamp)

I have a question about this last round. It looks like a .22-250, but that was a Remington development. What is this one?



Very interesting collection and I know nothing about many of these.
Can someone provide a little background on the .412 Winchester and the .308 “Fat Case”?
I had heard that Winchester had discussed bringing to market a cartridge in the .412-.416 caliber range when they were developing the .458 Winchester Magnum. This is the first prototype I have seen.
What was the .308 “Fat Case” based on?

Thanks to Paul for sharing his acquisitions.



Hello Paul, nice collection!

The .22-250 Remington prototype doesn’t belong to this series because, as you say, was a Remington development.

You may also want to look for the following variations:

  • .243 WCF: no headstamp & SUPER-X 6mm WIN (last one called “pre-series”)
  • .30-80 WCF: There are two variations of this cartridge both unheadstamped and with 150 grs Silvertip bullets. One has a 49.7-49,8 mm case and the other a 50.2-50.3 mm one (total lenght is different too).
  • .356 Winchester: no headstamp
  • .358 Winchester: WCC 53
  • .375 Winchester: no headstamp



Great group of cartridges! Thank you for sharing.

Could the “.22 Winchester” possibly be a rimless prototype developed as a replacement for the .220 Swift? The rather quirky semi-rimmed .225 Winchester was marketed to do this, but it would seem likely that there were other variations experimented with. Or maybe Remington simply beat Winchester to the punch launching a commercial version of the .22 Varminter? Hope to see more comments on this one!



Thanks all for the comments thus far. I received some information from Ray Meketa that I’d like to share here. Ray provided pictures of the boxes below. Ray also wrote an article for the Journal (#463) on the 30-80 WCF, which is a must read.

I should have said in my original post that these rounds came from a retired Winchester employee, and have no reason to believe that the ‘.22 Winchester’ is not a Winchester round. Ray agrees. He thinks that this .22 cal round is simply an example of their own pre-production prototype of the .22-250. As Ray points out, the 22-250 wasn’t developed by Remington, it was a wildcat from pre-WWII and Remington simply added it to its commercial line in 1965. Winchester may have been considering doing the same and Remington beat them to it. It is also worth noting the observation that the base of the .22 cal round ‘looks’ like a Winchester – it certainly looks like the other Winchester rounds, and as Ray notes, there are very few unheadstamped Remington rounds to be found.

Ray goes on to say that Winchester was looking at developing the 22 caliber on the 7.62mm NATO case in the early 1950s but the case is a little too big (capacity) for a 22 and they eventually abandoned the idea. Of course, they did introduce the NATO case in 6mm, 308, and 358 calibers.

The label on the box of the “fat case” prototype calls it a Caliber 308 Magnum. It was loaded with a 150 grain Silvertip at 2979 fps with a pressure of 47100 psi. As far as I know, it was new design, apparently from the same period as many of the others (1950s & 1960s).

Note the reuse of the .405 box for the .30-80 WCF round.

Fede – my 30-80 WCF round has a case length of 50.35mm.

Brian - one other interesting feature of the .412 was that it was fire formed in a chamber that had a pressure test hole as the case shows a sharp and distinctive circular bulge. Remnants of writing on the case wall indicate that it dates from ca. 1958.


It would be great to see a Winchester box for that “.22 Winchester” prototype to confirm its origin.

The .412 Winchester was developed in 1956. Here is a picture of the box:


Two more prototype boxes.


I am astounded at what I have learned from all of you over the years.
It is truly amazing!
Thank you for the education.



Could the .22-250-type cartridge be a .22 WOS (Wotkins’ Original Swift)? Wotkins was reportedly displeased when Winchester adopted the modified 6mm Lee case for the .220 Swift instead of the .250 Savage that he had recommended.

Also, what case family is the .408 Winchester based upon? You could get something similar by removing all of the body taper from one of the .30-30 family of cases.


The .408 Winchester also exists as an unheadstamped brass cased H.P.T., with a red base & bullet . No record here, of the .408’s parent case

The .30-80 WCF also exists in the long case version with a Western ‘open point’ GM jacketed bullet showing the knurled ring mid-ojive.

The .308 Fat Case Magnum also has two case lengths; 50.83 mm and 51.0 mm, both with the 150 gr. Silvertip bullet, plus the 51mm case also exists with a GM jacketed, magnetic cored bullet with a black tip.

The .338 Win. Mag. also exists unheadstamped in a GM jacketed soft nose with a pointed bullet and a GMCS jacketed bullet with a very blunt round nose.

This same GMCS jacketed blunt round nose bullet exists heavily crimped in a case headstamped “338 WINCHESTER (over) MAGNUM” with a struck nickel primer, and a large hole about mid-case, through which, a wood distance piece can be seen.

The round in question is a .22-250 Remington prototype, and it certainly looks like an Olin product, but I have no record of who actually made it. If the retired Winchester employee says they (Winchester) made it I would accept that as gospel.

Neat seeing the .412 box. My understanding is that those bullets were ‘hand made’ by Winchester & for what ever that is worth, mine has the same case budge.

An excellent bunch of Winchester prototypes, good on ya Paul.


Both the 264 Winchester Magum and 338 Winchester Magnum exist in headstamped cases without a belt.


I’ve just got an update on the identification of the .22 round. It is a 22-250 made by Winchester, but before they had a bunter made up.

BTW, the retired Winchester employee sent me a short list of some of the rounds he still has available. If interested, drop me a line.



Is the 308 Fat case made reforming a belted magnum , shortening the original case and lathe turning off the belt?

Again, I can’t see how the 284 Win can have a military headstamp. What was the parent case for this experimental round?


Paul, interesting information. I would like to know when this cartridge was actually made.

After reading Winchester’s 1967 catalog I noticed that this is the only “Remington caliber” (as we know it today) that is not accompanied by the Remington name. You can find cartridges like .222 Remington, 7 mm Remington Magnum, .30 Remington, .32 Remington, etc. all described exactly that way. The .22-250 is listed only as “.22-250” and is the only “nameless” caliber in the whole list.


I checked every single year of Winchester and Winchester-Western catalogs and it seems that it was finally listed as “.22-250 Remington” in 1975.


[quote=“Pivi”]Is the 308 Fat case made reforming a belted magnum , shortening the original case and lathe turning off the belt?

Again, I can’t see how the 284 Win can have a military headstamp. What was the parent case for this experimental round?[/quote]


There’s no belted case that could have been re-worked to produce the 308 Magnum, and even if there was, doing such a thing is not something that a major manufacturer would do.

In all liklihood, Winchester simply used an existing bunter in manufacturing the 284 prototype.