Mr. Bramble:

Thank you again. I do fit barrel threads very close, but have never tried lapping them in. I may just experiment with that. Howsomever, even with a perfect barrel fit there is so little metal left in the Farquharson receiver ring, from the extractor cuts, that I would not count on getting any extra strength from there.

I will have a look at Brownell's for the cutter. That would save setting up and grinding one.

Mr. Martini Guy:

Thanks for the information on barrel threads. I reckon if the Martini could hold a cartridge that size then the Gibbs can as well. As for the chambering, I want something "proper" for the rifle and, if we go with a .45, it will be the .461 Gibbs.

I found the proof charge for the .577 listed in one of Winfer's books: an 800 grain cylindrical slug on top of 330 grains of black powder. Proof pressure between 9 and 10 tons. That would be one big bang!

Best to all,

Glenn