7 x 66 S.E

Does anyone know the real story behind these two cartridges??

HS = Vom Hofe 7mm Super Expr.

I’m sure most of you are familiar with the story in COTW. But I know of a couple of shooters who have old rifles chambered for the cartridge and neither have seen the double shoulder cartridge.


Where did the double shoulder cartridge come from? Is that what is called a modified venturi-style shoulder?

Ray: I have a couple of these rounds with out the double shoulder, I do have a few Herter’s with a double shoulder there was no sucess or major improvement so they where dropped really quick. Is it a wildcat or a faulty die reject which was missed by quality control? Vic


I really don’t recall where I got it. In the proverbial cigar-box of mixed ammo?? I’ve had it for 15 years or so. I just assumed it was some sort of European wildcat and never paid much attention to it until one day I happened to see a reference to it in COTW.

Does anyone out there have one?? If so, how do you catalog it??

Surely I’m not the only one on the Forum who has one.

Vic - exactly what were those Herters cases you mentioned???

COTW refers to the unique shoulder shape and one of the older editions (ca 1972?) even has a photo of it. But their description of what it is really doesn’t do a good job of explaining it. It shows a photo saying the double shoulder is the result of fire-forming and yet the photo of the (factory?) cartridge shows the same unique shoulder. Later editions of COTW show a cartridge with a regular shoulder. And the only two rifles I know of have a conventional chamber.


Herter’s came out with a set of double shoulder cartridges and of course they where the best there ever was according to George but they never made too many I got mine from a wildcat’ter. .247 Herter’s Missile, 247 Herter’s Ram, 270 Herter’s Ram, 300 Herter’s Ram. They where featured in one of the last books written by the Herter family. With out the book no one I knew had ever even heard of them. Vic

the second one was fired in a rifle with the double shoulder chamber configuration.The intent was to reduce pressure peaks tha this very hot cartridge generates.This kind of chamber was tipycal of old rifles in this caliber,but not every 7 X 66 rifles have this chamber.I have a fired case that is like yours

I forgot to say you that the second cartridge in your photo ,having the case been fired in a double shoulder chamber, is a reload.New cartridges in this caliber have the normal shouldered case.However,reloading so modified cases isn’t a good thing.Some authorities say that the case MUST be reformed to the original shape before handloading it.


Thanks for that explanation. That answers a lot of questions.


Now that you mention those Herters names they do ring a bell. I don’t have any in my collection although I do have some of the Wasp Waist bullets.

Thanks everyone.