Hi Gents, anyone know how much is work is needed to get the 577 nitro 2 3/4" into this action. Is it a basic rebarrel and some tweaking? A couple of these are now circulating here in Australia.

I have never handled a martini henry in the flesh, can the old furniture/stock be retained or is it too small or also shake fillings loose?

I'd like a cheap 585 again( sold my Nyati variant decades ago) and looking to keep keep costs right down. This gun will likely never see big game

Around 30-40 years ago (damn, getting old!) I had one of the Greener shotgun versions of the Martini rebarreled to 577 3". Intended to shoot blackpowder loads in it. The action functioned fine and was able to feed a dummy 577 3" round I had with no issues. Other projects came along and it was put on the back burner and I eventually sold it on this forum. I think the person who bought it let me know he sold it to someone else. But again, to answer your question, all I did was have it barreled and the extractor modified. It worked fine.

The early Police shotguns had a solid frame and many prefer those to the split frame takedown Geener GP (general purpose) shotguns for conversion to rifles.
I’m not thinking that the split action is a real concern as the barrel will certainly be of good steel and the thread is quite big.
As long as loads are kept within reason which is likely as you probably won’t enjoy hot loads in such a light rifle anyway.

Interesting fellas. There are a few gents I know in my state who are interested and currently looking at options.

HA! I am the fellow who bought that Greener from Congomike many years ago. I loaded a dummy round with a 650-grain Woodleigh to ensure that it would go "round the bend" and it did. I then loaded a shell with enough black powder to be compressed by the Woodleigh and fired it just to say I had done it. Congomike's .577 Greener now lives with a very keen Martini aficionado in Edmond, OK who has been working up full nitro loads with it.
Here is a photo of a .577 3-inch case and a Greener action, but I don't think this is the Greener I bought from Mike.
This is the sort of mischief one can get into reading too much Samuel Baker!

Bill, thanks!
Always wondered what finally happened to it. I had thought of shooting full nitro loads, but back then not much information easily available on the strength of that action, so was going to stick with black powder. The one problem I thought of, was getting enough weight on the gun to use full nitro loads if I went that way. Again, thanks for the update.

Mike, my friend Douglas told me he loaded a full charge of one of the ReLoder series and the recoil was so stout he lost hold of the rifle -- and he has hunted in Africa with the .577-450.

Bill:
Glad it wasn't me. When i first envisioned the rifle, I considered everything but the weight. Seeing as most .577 doubles tip the scales at 12 lbs or better, I was trying to figure out where I was going to add lead bars to gain weight. Not a lot of room in the stock or forend. Anyway, again, thanks for the update. If you ever get a chance, I would really like to see a pic of the completed rifle if you it is available to you. You could PM me a pic, or I can send you a phone number for a text message, or an email address. Take care.