full blown nitro

[Dennis]

Beautiful rifle and a great caliber. Congratulations. I love double rifles.

Dennis

[Bill Murphy]

Richard, that would be a 40 caliber rifle. Keep trying the nitroexpress website. If you are unsuccessful, PM me and I will give you contact information for CaptCurl. He is an experienced double rifle reloader and has an astounding collection.

[Eldon Goddard]

That is a great all around caliber and can be used for some game in the U.S. unlike some other cartridges. I think the .450 range and up has very limited uses here. If you work up a load you should post your results here I would like to see if you get your load to match what it was originally regulated for. I

[edgarspencer]

I had a 450-400 3 1/4" H&H Royal grade sidelock, and it was a brutal beast using Kynoch ammo. I tried reloading it and the only loads that would shoot to the same point of impact were equally punishing. Since the only cases available used Berdan primers, and the Kynoch ammo was available, I gave up trying to reload it, and just shot Kynoch. The gun was overpowered for virtually any North American game that I hunted. I guess it would be good enough medicine for Grissly.