Interesting wildcat found

[prosper]

Today at the range I found a few interesting pieces of brass. Looks like someone was fire-forming a wildcat cartridge, and tossed a few whose necks had split in the process. They're headstamped '300 win mag,' but were necked down to 7mm and the shoulder was blown way forwards and steepened (looks about 40* or sharper), giving only about a .190" neck.

Anyone heard of such a beast before?

 

[todbartell]

maybe someone fired a 300 win mag shell in a STW

Chopperhead, are you out there buddy?
​

 

[prosper]

Naw, the shoulder is much too steep and too far back (it's shorter than an STW)

 

[prosper]

oops, wrong thread

 

[Mystic Precision]

I believe this is the 7STB - 7mm Super Throat Burner

Trying to approach STW performance in a standard length action by wildcatting the WM is an interesting thought but OAL of the mag will be the limiting factor. The bullet will be pushed as far into the case as in a 7RM and will limit powder space.

Peak pressures may be a bit lower but mechanically, that short neck could lead to problems in holding that bullet true while surviving the rigors of hunting.

I really doubt that this would be a target rifle as they are so many much better options.

In hunting length barrels, I doubt this project will pan out much gains over the 7RM. Better choice would have been the 7mm Dakota or a shortened 7RUM (same thing).

More useable case volume and the chance of improved velocity.

Jerry

 

[RR]

Prosper

7mm Super Mashburn Magnum had a case length of 2.625.What does that one measure for length.300 win mag is 2.62
Rich

 

[dan belisle]

Might be a 7mm Yukon (necked down 300 Win Mag, fired in an improved chamber). I know a fellow out by Evansberg that shoots one. There's also the 7x66 Argentine, but I don't think that one is improved. - dan

 

[prosper]

Prosper

7mm Super Mashburn Magnum had a case length of 2.625.What does that one measure for length.300 win mag is 2.62
Rich

It's 2.625 long