What do you know about these? Seyfried made reference to it in his article on the .600 Nitro in Double Gun Journal. Thanks.

SSK Industries blows out a .577 NE case to hold a .620 bullet, because the .577 NE case head is the biggest thing that will fit into a Ruger No. 1.

Fireforming those cases will be very expensive and painful.

And the cost of SSK guns is such that a lower end double could be purchased.

But if you could build a .620 rimless in an action smaller than a 50 BMG action, I would be very interested.

Why would you want rimless? I don't even want my .300 Whisper to be rimless so I ordered a barrel based off of the 360 Dan Wesson brass. Never saw the point to having rimless especially in big bore singles/doubles that may get into a fight.

I want a .620 rimless that holds 3 in the magazine and 1 in the chamber. I prefer bolt rifles, and a rim on a bolt is a hassle.

Hi Yukon,

The 600/577 Rewa was developed for a double barrel rifle Holland & Holland made for his royal highness the Maharajah of the Indian State of Rewa. H&H build a royal hammerless ejector double for him. The correct name of the cartridge is .577 Rewa. It is based on a necked down .600 Nitro Express to take a bullet of .585 dia. It has a shoulder ( like the rimless .577 Tyrannosaur ) and is not the same cartridge as the necked up 600/577 from SSK, where ( and here 500grains you�re a right ) a .577 NE is opened up to take a .620 bullet. The 577 Rewa will deliver 2150 fps with a 750 grains bullet. Holland & Holland still has cartridges for it and at least another pair of double rifles has been build a couple of years ago. It is not a wildcat, it is a very rare factory loaded cartridge.