Is there a rimmed rifle cartridge ........................

[breacher]

..............with the same dimensions at the base, as a 12 bore cartridge ?

I am guessing one of the old "elephant gun" calibres ?

[wildrover77]

..............with the same dimensions at the base, as a 12 bore cartridge ?

I am guessing one of the old "elephant gun" calibres ?

There was a short period when elephant guns were in 8, 4 and even 2 bore. They died out quite quickly as they were not that effective, smaller diameter and higher velocity was more efficient. Also the recoil was horrific.

[breacher]

I am thinking more about 12 bore brass cartridges necked down to rifle calibres.

Found a couple - .500 American and .600 African......................

[davidh195]

Use 12 bore brass to create Tabbatier cases.

David

[Charlie Muggins]

Okay Breacher, what 12-bore are you thinking of mutilating?

[Sandgroper]

70-150 Winchester http://gunsmagazine.com/winchesters-rem ... odel-1887/

According to Winchester historian, George Madis, three, rifled-barreled, Model 1887s are known to exist chambered for the .70-150 Winchester cartridge. That’s a .70-caliber cartridge formed from a brass 12-gauge shell pushing a bullet weighing 700 to 900 grains by 150 grains of powder. A real stomper round on both ends!

or have a look in the library http://www.full-bore.co.uk/viewtopic.php?f=36&t=5196

[breacher]

Okay Breacher, what 12-bore are you thinking of mutilating?

Oh just thinking out loud..........

[Jim_GSXR1000]

.700 NE 1000grain bullet

[Chapuis]

How about a 12 bore rifle, not a paradox but a true twelve bore rifle.
A friend had one some years ago and he took several large species of game in Africa with his including giraffe. I'm not too sure on the make of the rifle now but I think that it might have been a Bland.