577/450 Martini Henry

Making the Ammunition – 577/450

While there is still piles of snow on the ground, thoughts of Spring are making me start planning for the first real shoot of the year. One of my favorite guns to shoot is the Martini-Henry. I have two shooters, a 1873 Mk I and an 1887 Mk IV, both with mint bores.

Casting bullets for this calibre is quite easy since while you can paper patch grooved bullets, smooth sided ones are historically more accurate and are easier to cast. The finished bullet weighs 520 grains, so you get just 13 bullets per pound of lead. Unlike the 577 Snider that requires the bullet to bump up to catch the rifling, the 577/450 does not really need to. So no special alloy is needed, although the addition of some tin makes casting the small cavity in the base easier. By adjusting the paper weight, it is possible to adjust for variations in bore dimensions and ensure the best accuracy. While it is good to have several weights of paper to see which one works the best, typically 9 lb onion-skin paper is the one to use. However for over-size bore, heavier paper will be needed.

In the photo you can see how we move from the unpatched bullet to the finished one that is coated in a mixture of beeswax and petroleum jelly. The loaded round is next to an original military load. One thing to note is the need to slightly bell the case mouth so that the paper jacket is not damaged during seating. Once seated, just enough crimp should be applied to iron out the belling. Unlike the originals made from brass foil, Bertram cases are much more robust and no special care in handling is needed. The lube on the paper patch does not make it completely waterproof but it is certainly water resistant.

The choice of blackpowder or Trail Boss (or reduced loads of smokeless) depends on your objectives. Using blackpowder is more complicated and I am not going to comment on loading it in this blog but will in a later one.

I need to get back to work and finish the patching and give the bullets time to cure. Doing this is a great way to connect with the past; watching the cloud of smoke and hearing the solid “smack” of the bullet on the steel plate makes for a great day.