Thread: Which calibre for a Martini Henry project?

Originally Posted by gundoc

Bear in mind that the Matini-Henry action needs to have the firing pin diameter and protrusion reduced and a hardened steel firing pin bush fitted into the face of the breech block before they are safe to use with high-pressure modern cartridges (eg. in excess of 40,000 psi) or the cartridge pressure can force the large diameter firing pin backwards when fired. This results in a ruptured primer, severe gas erosion of the breech face, and hot gases in the face of the shooter. The .303 Martini-Enfield actions usually have had this modification done in the 1890's when converted at Enfield. Personally, I believe that your best ruults will be with the .45/70 and leave the hotter cartridges to more modern actions.

Thanks, I'm unsure if either of the actions were from .303s or 577-450, that may dictate what I do with it, but there's something very cool about a .45/70, even if I only use cast bullets over Trail Boss

Originally Posted by tommygun

Thanks, I'm unsure if either of the actions were from .303s or 577-450, that may dictate what I do with it, but there's something very cool about a .45/70, even if I only use cast bullets over Trail Boss

Nothing wrong with that. Or you could do a cowboy action load from the ADI book which is a little faster than the trail boss loads.
Once I shoot all the trail boss loads I have I will do the cowboy action loads. Only have about 100+ to shoot.

45/70

Anyone know where I might find a cheap .45 calibre barrel then?

If the block was converted to .303 it will have a dovetail machined into it's face and a wedge fitted in with the smaller firing pin hole.

9.3x74r

Looks like one of the receivers has the dove-tailed bolt face and the other doesn't, also it turns out the guy looking to sell it already has a 7x57R barrel destined for it but is missing a part from the action. Could still be a cool project maybe sell the 7mm barrel and get a .45-70 =)

Hopefully you have a 303 ejector in your glory box, much easier to adapt than a 577/450 one.