Your Gunsmith is right and wrong. It depends how you are hunting. In a blind or bayed up with digs, I would use a Martini. Stalking or jump shooting, probably not. Out of a helicopter, nope.

I use the Martinis big and small for hunting.

and thousands of round through the little Martini's.

Are you sure it's bubba'd. Citadel made some real unusual configurations

Any greener shotgun action is an action to be avoided for building, they are difficult to work on. Greener's first line of instruction in disassembly of the gun is "Do not Disassemble unless absolutely necessary". I do not like them. If that EG action is the split action-takedown, it is not recommended for centerfire rifle cartridges. The other problem with the Greener shot gun is that they are the ugliest Martini ever made.

LoC was 85 grains of RFG2 powder and 480 grain.

John Taylor refers several times in book to his gold inlaid short sporting Martini Henry, as one of his favorites for Lion. In my quest to acquire a true Martini Sporting rifle I have found a large number of well worn 577/450-it seems that is there were lots of these, similar to the Rosier pictured. I have found less used examples in other cartridges, but not 577/450.

The Kudu above was shot with 577/450 in ZAR Westley Richards military Rifle. Shot quartering away, the bullet passed completely through the animal hitting just in front of the left hip and exiting through right front shoulder and dropping the animal where it stood.

Will a 45/70 or 577/450 kill buffalo, I have no doubt. Are they great killers, I have doubt. I have heard of Grizzly bear being killed with .22's also, But I would not consider a .22 for Cape buffalo. On the other had were I out in the bush hunting with a .22 and cape buffalo attacked me, they will find a pile of empty .22 casings all around my mangled corpse.

I am currently looking for an example of Martini Sporting rifle in .303. I have found two in Europe greatly over priced. One in France a Bonehill, the seller wasn't willing to export to US. A second rifle a beautiful Army Navy sold gun in Germany was mutilated- rechambered from .303 to 8x57 JRS and the top rib cut for a Schmidt and Bender scope in EAW style Claw mounts. Sacrilege.

I am unaware of jacket 577/450 Martini bullets, but it only seems logical and reasonable for there to have been.

The original military bullet was 480 grain. The twist in a military Martini Henry is for a 550 grain bullet. I've seen reference to that group of original style hunter also. Sounds fun.

DoubleD- Douglas just found a niche a few years ago and started studing. They told us in College, this is what we should do. it took me almost 20 years to find the niche, 20 years ago.

I am with you here. Being in the high risk group, old-male-heart disease, for this stupid disease and being married to a former widow, my activities are severely curtailed. She says she buried one husband, she isn't burying another. I say, I buried one wife, I'm not burying another. Sounds like one of us is going lay in the back bedroom for a while, until the second one goes. But any way she is very vocal about any activities that might bring me in contact with others.

Actually two different issues, but one leads to the other.

The Martini system uses an inertia extractor. You must open the lever with vigor, snap the action open to make it function. It is a poor and weak design.

If you breech the action up to tightly, the cartridge does not have room to expand and contract when fired. To many people try make the cartridge head space off the shoulder or achieve zero head-space. Because the Martini has a rotating breech block, it is near impossible to have zero head-space. There should not be any interference between breech block and barrel/cartridge when the breech is closed. When closed there should be a gap between breech face and cartridge. That gap, distance between breech face and go head is what is measured. If you use a standard no-go gauge you may get a false reading. Standard breech for the Martini is no more than .010 gap between breech face and head gauge.

And then you add soft primers.

And them you shorten the striker spring to ease trigger pull (wrong way to go about it)

The Martini action is a bundle of stacked tolerance causing problems.

Seems that every .22 K-Hornet I built had this issue. The worst was the one I built for my late wife. Now there is a gun you want to get right, one for a spouse. If wife has problems with a gun you built, you will have problems with wife.

As mentioned it was RFG2 and that is Rifle fine Grained supercsript 2.

That soft bullet won't reach that .464 cylinder section until it has passes 8 inches from the breech end. In the mean time it starts it obturation in a section of smooth barrel at the case mouth that is .5075" and .468" groove when it hits rifling. Dr. Mann studied obturation and how to control it. The problem he discovered was that obturation was not uniform, but rather at times lopsided.