Martini Henry

[Greg G.]

Question to those that might know about this. Just got a Mark 4 MH and slugged the barrel to see what size bullet to start loading. Started at the muzzle with a .457 lead bullet thinking that it would just slide through because Mark 4 barrels are supposed to be .468 or better. I had to pound it down the barrel the first 12" until I got to the tapered part or the barrel then it slide down the rest of the way to the breech easily. Looked at the bullet and found that it was marked with by both the lands and grooves. Is this normal? I paper patched a couple of bullets to .468 but cant slug from the breech end without removing the barrel. I guess I was wondering weather or not to shoot the PPB and let the taper squeeze it down to the muzzle size. Don't know what the groove measured, not easy to get a good number, but a .457 slug is a bore rider for the last 12" of the barrel. Hope this makes some sense to someone, I guess I wasn't expecting to have to drive a .457 slug down a Mark 4 barrel and have it ride the bore. It's almost like I have a Mark 3 barrel on a Mark 4 receiver.

Thanks for any info or ideas on this.

[salpal48]

I have several Martini Henry's. What the books say and what You end up having are different. If you Have the Nepal rifle are worse.
The sported I have i use .459 . . The Military are another story up to.470
. Once They were shipped To those countries No one know what were done to Them. They all shoot very well. Small diameter Boolits or large . To me It makes no difference

[fgd135]

I shoot a couple of Mk1V's, and use .459" 480 grain slicks patched to .471" with 16# 100% cotton paper. Accuracy is good with black powder, and with 5744. I've also used a .468" RNFB grease groove bullet. Your .457" bullets are going to be very undersized in a Mk1V, but might work in a MkII with a smaller diameter bore.

[curator]

You can make a cerosafe casting of the "throat/leade" and get an idea of the size you should make your boolits. My MkIV slugs .476 in front of the chamber. I cast the Lee .475-400RF boolit of pure lead with 1/2& tin and lube with bee's wax lard. The slug drops from the mould at about .480 but thumb seats nicely in fired brass without sizing. Chambers fine in my "converted CBC 24 gauge brass. 80 grains of Goex Fg with Kapok filler. Great accuracy if you don't mind the recoil.

[Greg G.]

Curator,
I've read many posts by you and others on this site and believe what you are saying about the throat and the taper of these guns. I have some cerrosafe on the way and will do as you say, just didn't expect the muzzle to be as tight as it is. Kind of thought that a .457 lead boolit would just slide through with little to no resistance maybe just mark the lands but not the groove as well. I have 10 rounds loaded basicly coping your loads but with Bertrum brass and was going to shoot them but backed of because of the muzzle size. Will post more later after making a cast of the throat to see where it is at.
Thanks to all for the info, guess I'm careful, don't what to blow anything up.

[Greg G.]

So finely got my Cerrosafe the other day and did a chamber cast. Measured .472 after an hour so I'm good to go with the PP .459 405 grain lead boolit, it measures .474. So now it can try it and see how it shoots. Thanks to everyone here for the advice. This is my first gun that uses a PP boolit and BP cartridge so there is a bit of a learning curve.