Mystery wildcat case ID

[alfadan]

A few years back dad bought these cases at a gun show. They were labeled as 7 tcu but that sure was wrong. They are a cut-down 30-30 and necked down to 7mm. I can't find any info online for this. When I get back to mom's I can look through COTW. Any ideas or maybe a one-off custom like a 7mm harrett?

293616

[cwtebay]

Looks like you are correct on not being 7 TCU. https://uploads.tapatalk-cdn.com/20211226/8883234b0b42841a58d0b927ba61302c.jpg

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[dk17hmr]

6.8 SPC Rimmed maybe/maybe not if the chamber was cut slightly deeper. I had a 6.8 contender cut for a counterbore to use 30-30 brass.

[country gent]

The 7mm TCU is based on a 223 case, but the dimensions listed are very close to the 357 herret wildcatt. I know Steve Herret had several wildcatts based on the 30-30 case for use in the contender. A little research in cartridges of the world or The complete guide to cartridge conversions may help shed some light on it. JD Jones also had an extensive line of cartridges for the contender.

[goste]

Is it possible, it's a 7x30 waters? I don't recall if it was rimmed or not..

[rintinglen]

Looks like a wildcat 7mm Bulberry or something similar. Too short to be a 7 x 30 Waters, and I know of no other factory 7 mm short rimmed cartridges.

[Skipper]

7mm Herrett

[alfadan]

The dimensions do seem to be closer to 357 harrett than 30 harrett, though it is a 7mm.

[jonp]

6.5mmUS or 7mmUS? Pretty close although I can't tell if your dimensions are inside or outside the casemouth. .

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[405grain]

I just looked on PTG's website. They carry a pretty extensive selection of chambering reamers for both factory and wildcat cartridges. They have nothing listed for "7mm Harrett". Keep searching to discover what this cartridge is, but it might be a "one off" wildcat.

[Greg S]

7mm International Rimmed.

[high standard 40]

7mm International Rimmed.

Not a 7mm Int Rimmed. The 7 INT R uses a full length 30-30 case. I agree with Jonp. It is likely a 7US.

[alfadan]

Thanks guys, looking at it I agree it is 7 US; what an oddball cartridge. These may have been from someone with a Wichita Arms pistol for silhouette shooting, as he bought them at a wichita gunshow. I have 47 pieces of it I may try selling in the swap shop.

[jonp]

7mm Ultimate Silhouette (7mmUS). That is an odd one to run across.

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[cainttype]

If your photo with measurements is correct, and .280” is neck OD, it is not 7MM (.284”).
You have to account for the neck wall thickness, so “if” you used a thin neck thickness of .010” (x2) you’d be likely at the 6.5MM bore diameter at this point, accounting for neck tension when seating a bullet… .012”-,013” neck walls gets you closer to .257” bore.

[alfadan]

Sorry should have been more clear; it is .280 ID

[waksupi]

For a wildcat, it could be something that had been in existence for years, then another experimenter came along and invented it again. I'm glad didn't find it, that would have caused me to find a reamer, and cost me a new barrel and action to build a rifle to try it out. Back when the Bauska Rifle Barrel shop was selling off, there was a drawer full of John Buhmiller's wildcat reamers. I was tempted to buy some, but knew my weaknesses, and the path it would have led me down.
It's obvious to me the only thing for you to do is make a chamber casting, send it off to Pacific Tool, get a chamber reamer made, and continue ad infinitum down the steep and probably expensive trail. It's just what gun guys do.

[45-70 Chevroner]

Is it possible, it's a 7x30 waters? I don't recall if it was rimmed or not..

The 7x30 waters is a full length 30-30 case necked down to 7mm. I had one in a Thompson Contender and all I had to do was run it through the 7mm decapping full length sizing die and load it as usual.

[45-70 Chevroner]

Sorry should have been more clear; it is .280 ID

The .280 is considered a 7mm. Just think about the 280 Remington. Your wild cat could possibly be a Harrett attempt at a new caliber that did not work out, the reason I think this is the shortened case. If I'm not mistaken all of Harretts attempts at wild cats was on shortened cases.