The load is not marked anywhere on the rifle. I'm hoping that the "230" on the barrel flats is the bullet weight and that the "80" on the barrels is the powder weight. COW says that the bullet should be between 210 and 290 grn and the powder charge should be between 79 and 84. It sounds good anyway. That's where I'm going to start. What do you think?

Mike:

I would say from the location of the "80", it is the pre-rifling plug gauge diameter of approx. 0.388".

Kind Regards,

Raimey
rse

Bore is .415

Mike:

With that, I would say that the plug gauge pusher was conservative and rounded down to the integer "80". Does the rifling have 7 shallow grooves and a degree of spiral about 1 turn in 22"? Some of those bullets were coated w/ paper atop a wax wad for lubrication. Lovely tubes, are they laminated?

Kind Regards,

Raimey
rse

They are damascus and have 7 fairly deep grooves. I haven't measured the twist yet. I'm hoping to stay away from paperpatch. I like to keep things simple. But, if it needs it I'll use them, I already have the paper.

Mike,

I have a Holland in that caliber. A 230gr. bullet with 80grs. of BP is the BP load that regulates my rifle. Perhaps the 290gr. bullet was used in the NFB load. I don't think I can push the 290gr. fast enough with BP to regulate.

I hope your shoots as well as mine! Great little rifle.

Craig

No. These are standard pre-1887 Birmingham marks. Bore size was a required mark after 1855, and still is today. Until 1887, bore diameter was marked in gauge for both shotguns and rifles. This was stamped between the definitive proof mark and the view mark, as it is here. The "80" is unquestionably the bore diameter in gauge.

I don't know what the 230 on the flats is. During this period, while the maker might well engrave load data somewhere on the rifle, it was not stamped by the proof house. The absence of load data stamped on the flats or underside of the barrels on a rifle of this period is normal.

Bullet diameter seems to have run .403" to .408". I think I'd slug it again.

Nitro thats what I thought about the proofs but I've had more than one person tell me that the 230 grain bullet and 80 grain black is the usual load for either thier personal gun or in one case the custom loader said that's what he usually loads for this round. I'll try it and see.

When slugging your bore you may get an undersized reading from the odd number of "spires and flats" (for henry patent rifling, rather than lands and grooves for the kind of rifling we're used to now). You'd be measuring spire to flat; try rotating the slug between the caliper jaws to see what its maximum diameter is, or better stil, try ring guages if they're available.
It's a trap a lot of Martini Henry enthusiasts run into when slugging their bores.
RG

Mike,
I just received a copy of the Kynoch Ammunition catalogue from 1884. It has a drawing of a ".450 reduced to .440". It has all of the measurements. If you like I can copy it and send it do you as a PDF file.
Frank

Frank I just saw this. I'd appreciate it. mharrell@cpgh.org