You can buy Federal Ammunition 470NE ammo loaded with 500gr Trophy Bonded Bearclaw softs and 500gr Trophy Bonded Sledgehammer solids. I think Federal still offers Woodleigh 500gr softs and solids too. Woodleigh solids have worked well for me for buff.

You can also get W. Rommey ammo form Westly Richards if they have it. Woodleigh softs and solids I believe.

Might try Griffin & Howe for ammo very likely they will have it, not sure what brand they carry.

You can call Superior Ammo and he will provide 470NE ammo. You can try some of his ammo and see if it shoots to regulation. If the ammo needs speeding up or slowing down he can custom load it for you.

None of the ammo choices above are inexpensive. If you reload, or have a friend, gunsmith, etc. who will teach you you will be able to taylor your loads to get the most potential accuracy from your rifle and at considerably lower cost. Might be a good idea to go to the double rifles section here and do a search on regulation so that you know whats needed to get your rifle shooting to its potential.

Graeme Greene's book "Shooting the British Double Rifle is extremely informative and a good and nessecary read too, if you want to get the most from your rifle.

Good Luck.

JPK