Weatherby Magnums

I have examples in front of me that I know are mady by Norma, RWS and Federal Cartridge Co.

I also have some headstamped “WEATHERBY ### WBY MAG” Made by an unknown company. They have a very US made look to them. The headstamp letters are smaller and more weakly struck than the Norma or RWS rounds. The primers are nickel plated and very flat. The bullet also have a US made look to them, with fairy pointed ogives and knurled cannelures. The calibres are .270, .300 and .340.

Where was the Weatherby company based? So I can put in my records as "Made by ??? for Weatherby Inc., Based in ???.


WBY started out in California and are still there for some reason. Weatherby ammunition has been made by several companies, in the States and overseas. Collecting WBY cartridges can be a specialty of it’s own.

Do a search. WBY ammo has been discussed several times in the last couple of years.


I just had a quick look, I can’t seem to find any pictures of headstamps that look like mine. However, the Norma and RWS ones are shown. These cases look to be recent made (last 20 or 30 years).

When Weatherby has it’s cartridges made, not all have the makers headstamp. most of the norma cartridges do not have any indentification except on the original box, RWS is on the primer but Weatherby also made unprimed brass. Speer, Federal, and PMC made a small number of select calibers, I have have only 1 speer and 1 Federal both of them have their name on the headstamp. norma does use a green annulus seal on some of its rounds, and a NP on some of its primers, again it will produce unprimed brass also. As a side note many of Roy Weatherby rounds where based off of the 300 H&H mag and you will see some of the original wildcat cartridges that have been made. Vic


I have one of those early 300 WBY cartridges made from REM-UMC 300 MAGNUM cylindrical brass. I was trying to get more documentation on it and posted on this Forum as well as a couple of Weatherby Forums. No response at all. Do you know anything more?


Ray: My Wby is the 257 necked down, I was told by the seller it was done before commercial brass was readly available. I have to look but I think the 257,270,300 where all based off of the same brass, 300 Mag. Vic

I have this headstamp,I think it is a norma product.
Could it be found on other weatherby calibers?

WBY-N 338-378 WBY MAG

Of the 75 different Wby headstamps the 338-375 is the only one with N in the headstamp. On all of the other norma marked headstamps it is with the full norma name. Or NP on the primer.

Possible new question was this cartridge developed with norma? and for that reason it has the N in the name?

A-Square and Qual Cart are now also making Wby caliber cartridges.

Please can someone post some photos of Weatherby headstamps by makers other than Norma, Federal and RWS so I can compare them to my headstamps.

If your cartridges have WEATHERBY in the 12 oclock position of the headstamp, I think you can assume they were made for Weatherby by Norma or RWS. RWS only made them for a year or so beginning in about 1963. I don’t believe anyone else made Weatherby headstamp ammunition without including their own name in the headstamp. In looking at my rather large accumulation of .270 Weatherby boxes, the change in the headstamp from the original WEATHERBY 270 MAGNUM to WEATHERBY 270WBY MAG occurs after they changed from the old yellow, brown, and white ‘tiger in a red circle’ format. All of my tiger boxes have the original headstamp. My later boxes all have the newer ‘WBY MAG’ headstamp, and both were made by Norma.

Speer, Rem, A-Square, Qual Cart, Federal,all have their name in the headstamp. The ones you have to id is the norma/RWS. A green annulus is a indication for norma and a blue/purple annulus is directed toward RWS. But the color is NOT found on all rounds. Part of this was Wby action of supplying empty brass to it’s customers. Again RWS on primer is another point and a NP on a primer is for norma. Just checked, all of the for sure WBY MAG headstamp where made by norma. vic

A good discussion last year under the heading
Weatherby .375 Magnum headstamps / primer markings

So were the “WBY MAG” headstamps later Norma production than the ones with the dull grey “NP” primers, green annulus and almost coppery tone on the case head?

Hey guys

Now that you are looking at all of your WBY cases, how about my question?

WEATHERBY 300 MAG (with the NUM obviously ground off the bunter)

WEATIIERBY 300 MAG (Part of the H missing and ground bunter as above.)

REM-UMC 300 MAGNUM (made from cylindrical brass)

All the above are 300 WBY MAG


a wildcat case you sent me is headstamped REM UMC 300 MAGNUM too,but what was it?
A basic case or a unknown ( for me ) cartridge?

If the headstamp is WEATHERBY xxxWBY MAG, it is one of the newer Norma cartridges; I do not know when they started with this newer headstamp. Does anyone on the board know someone at Norma who might provide a date for this headstamp change, and while we are at it, dates for the different box formats, and an explanation for Ray’s missing 'NUM’s?

While we wait for some answers, how about an off-the-wall, highly improbable possibility that ties Ray’s missing ‘NUM’ and Falcon’s ‘WBY MAG’ headstamp together. Perhaps the ‘N’, ‘U’ and/or ‘M’ had a tendency to wear out sooner or break more often than the other letters in the headstamp, resulting in the need to prematurely scrap costly headstamp bunters, hence the grinding off of the damaged portion to made do until a replacement was available, and the eventual change to a headstamp that did not include these troublesome letters.

Ray and Pivi,
It is my understanding based on the reading material we both received from Glenn that Weatherby fireformed the 300 H&H Magnum cases he used to make his cases, prior to his relationships with Speer (short and unsuccessful) and Norma. I got the impression that these were fully formed 300 H&H cases, not unfinished cases.


The only problem is that my REM-UMC 300 MAGNUM cartridge has never been fired. (Likewise the 2 with the missing NUM) If it was a 300 H&H to begin with it would show some vestige of the original shoulder. Mine shows only some faint “stretch marks” at the double shoulder which would indicate an unfired case that was formed from cylindrical brass.


The wildcat that I sent you could be any number of cartridges. I’d have to see a photo to ID it. Quite a few wildcat cartridges were made from both 375 and 300 H&H brass as well as later ones that were/are made from WBY brass.


It is the 338 Improved magnum 40


It would have been made from a 300 H&H case.

The AMU cartridges are headstamped REM-UMC 300

Check your e-mail


I recently acquired a couple rounds that I think is a new Weatherby headstamp:


I believe it is brass made by Hornady.

Is a list available of Weatherby headstamps?