Considering joining the club...

[303 Gunner]

I like the idea of the adapter to .45LC .....still some bang, but at a much more reasonable price point. Original caliber ammo seems awful expensive, if you can find it...and I really do nt have the desire to hand load.
I will also look for the referenced .22 adapter...that's a cool idea, too. Are they available, in general? Are they affordable?

The .22s I'm referencing were full-blown conversions with new barrels. They were done by W.W. Greener and C.G. Bonehill for the British Society of Miniature Rifle Clubs as target rifles. The founding of the SMRC and the conversion of these .22s was in large part due to the poor performance of British riflemen in the Boer War, with the thought that a populace which already knew how to shoot could be more easily prepared for war. They are, in general, available, but not so much as the unconverted rifle. They run the gambit on price. I've seen anything from $600 to $5,000 depending on condition and who's bidding.

[82Trooper]

The .22s I'm referencing were full-blown conversions with new barrels. They were done by W.W. Greener and C.G. Bonehill for the British Society of Miniature Rifle Clubs as target rifles. The founding of the SMRC and the conversion of these .22s was in large part due to the poor performance of British riflemen in the Boer War, with the thought that a populace which already knew how to shoot could be more easily prepared for war. They are, in general, available, but not so much as the unconverted rifle. They run the gambit on price. I've seen anything from $600 to $5,000 depending on condition and who's bidding.

Yes, My bad. I misunderstood "conversion" (I was thinking "kit"). I did some subsequent research after you posted. Seems like a nice little package....perhaps for my "next" one?!!

[browningautorifle]

Yes, the rifles would likely perform better...but I have a lathe so I think in terms of what can be done.

[303 Gunner]

Yes, My bad. I misunderstood "conversion" (I was thinking "kit"). I did some subsequent research after you posted. Seems like a nice little package....perhaps for my "next" one?!!

You won't regret it. They're fun little guns! If you do pick one up, they seem to like .22 short, though it's not marked on the action anywhere.

[old tanker]

I have a Marrtini and had good luck using the steel adapter. Standard .45 Colt bullets are considerably undersize. Factory .45 Colt ammunition went bang reliably but the group at 25 yards you could just about cover with a poncho. Handloading, I found that reasonably good plinking accuracy was possible using hollow base bullets intended for .455 Webley. Cast from pure lead using an RCBS Mold 45-265-RN-HB and loaded over 5.5 grains of Trail Boss thy will do "minute of coffee can" at 100 meters. They work well with black powder too, but you greatly increase the risk of getting the adapter stuck if you don't keep things clean.

Lee makes a .454 Minie Ball Mould that some people say works well, the hollow base expanding to fit a Martini bore, but that I have not tried.

[browningautorifle]

the group at 25 yards you could just about cover with a poncho

Hard to coach that shooter...

They could actually be assembled on the firing line and shot too, deprime with a tack hammer and pin. Prime by hand and a powder scoop to charge, slip the ball into the case and chamber... Teflon tape around a bullet also tightens things up for these super low velocity loads.

[Patrick Chadwick]

Factory .45 Colt ammunition went bang reliably but the group at 25 yards you could just about cover with a poncho.

- No surprise. The factory loaded 45s would probably have a lead alloy bullet with approx. BH15 or more and would hardly upset into the bore.
Since the groove diameter of a .577-450 barrel at the breech end is something in the range .470"-.480" they are just going to rattle down the bore and not take the rifling properly.

Handloading, I found that reasonably good plinking accuracy was possible using hollow base bullets intended for .455 Webley. Cast from pure lead using an RCBS Mold 45-265-RN-HB and loaded over 5.5 grains of Trail Boss thy will do "minute of coffee can" at 100 meters.

Once again, no surprise. The soft lead bullets with a hollow base can expand to fill the bore much better. But the bullets are still too short to provide the kind of accuracy one expects from a rifle.

As you have already been bitten by the M-H bug, I strongly recommend that you search around here

Martini-Henry Forum - British Militaria Forums

where you will find more information on shooting M-H´s than anywhere else.

[old tanker]

As the OP was asking about the .45 Colt adapter, I offered what my experience had been with one.

Martini-Henry Forum - British Militaria Forums where you will find more information on shooting M-H´s than anywhere else.

I believe there is an "old tanker" there lurking behind the muzzle of a Vickers L7 rifle.

[Patrick Chadwick]

Oops! Sorry, quite correct, lost track of the thread. But my comments are still valid.

[browningautorifle]

Since the groove diameter of a .577-450 barrel at the breech end is something in the range .470"-.480" they are just going to rattle down the bore and not take the rifling properly.

So...with all that, a better choice for the sub cal chambering would be either .460 S&W or even .500 S&W to engage the rifling. They would still have lots of power and still be tame for that rifle. The problem however is wanting to shoot lead bullets and the OP doesn't want to reload his ammo...no factory lead loads are available that I'm aware of, although there are companies that do custom loading in the US aplenty... I would do it for him if I was even in the same country. Having a sub cal made and chambered would still be cheaper in the long run that laying out for dies, brass, bullet molds...or buying from someone that custom loads 577/450...

This gets more complex...

An addendum here...we discussed this a few years back and seemed to have it by the bag then. Here it is... https://www.milsurps.com/showthread.php?t=4843