I think the .577 2 3/4" is a wonderful cartridge. Of course, we really are talking about the .577 BPE and the use of nitro-for-black loads. Believe me, the .577 2 3/4" BPE was and is a formidable round capable of taking very large critters with aplomb.

I consider myself to be fortunate to own a magnificant rifle in this chambering (though I had to pay through the nose for it). It's an Alexander Henry double that I chased for some years. I shared it on this forum here:

Alexander Henry .577 2 3/4" Double Rifle

In the referenced thread I discussed my earliest efforts at load development, and there was an interesting discussion with Marrakai in which we speculate about when my rifle was made. It has a relatively high serial number yet pre-1887 proofs.

Here is an article I wrote and self-published in which I discuss some techniques I developed for loading paper patched bullets for this and other BPE rifles:

A Few Tricks With Paper Patched Bullets

Marrakai certainly telegraphs a strong message of how wonderful these rifles are. I also recall an article written by Sherman Bell for the Double Gun Journal in which he tells his experiences hunting feral buffalo in Australia's Northern Territory using just such a rifle and cast bullets.

Good stuff all.

Curl