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Discussion Starter · #1 ·
Folks:

I am ready to pull the trigger on a bullet mold for my Martini Mk IVa. I'm looking at the 2 cavity iron Accurate molds, particularly the one they label as being for the Martini Henry, #47-470B: http://www.accuratemolds.com/img/bullets/detail/47-470B-D.png

However, I've been thinking too hard and, reading the NRA Cast Bullet book, it is saying that barrels where the lands and grooves are of approximately even areas (like 2 and 4 groove Springfield barrels) use a bullet with a long, bore-sized nose, but barrels with the groove area larger than the land area (like the Martini) need a bullet with a shorter nose and a long groove sized body.

That would look more like Accurate mold #47-475XR: http://www.accuratemolds.com/img/bullets/detail/47-475XR-D.png

Can someone with experience in these matters lend me some of their expertise, please?

Thank you.
 

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Due to the unusual plan section of Henry s rifling,I would think it was a fairly involved geometric exercise to decide which of your categories the cross section fitted.Nevertheless,in my experience ,a bullet with a short round nose,and the rest cylindrical/lube grooved works best.The longer the bearing surface,the more likely is the soft bullet to exit the muzzle aligned to the line of flight.The theory of long bore riding noses falls down in a Martini because your thumb has to push the bullet into the throat,so it cant be tight like in a smaller bore bolt action.Either 470 or 475 dia will work ok.Regards John.
 

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Good feed back from Martyn and John. They are saying and you should not loose sight of, the MH barrel, H for Henry rifling is not a cylinder bore as the Springfield/Enfield rifle bores. Henry rifling is a series of flats and and v notches. The bullet is only supported at the center of the flat and the peak of the notch. And, just to make things interesting, the first 8 inches of the bore from the breech is tapered for 8 inches up from the breech.

To compare Springfield/Enfield rifle to Henry rifling is to compare an apple to an orange.
 

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I have two MK IV rifles and shoot the Accurate mold 47-465M. it is very accurate in my rifles, I have shot some 2.5" groups @ 100 yards with this bullet. I shoot smokeless and if you are going to shoot black powder this may not be best bullet do to the size of the lube grooves. I use a lube consisting of 60% beeswax and 40% Vaseline. I size in a lube sizer .470. I also use Lee 480 ruger dies to load the big case. Martyn with x-ring prepared the brass for me and it is exceptional.
here's the mold...

http://accuratemolds.com/bullet_detail.php?bullet=47-465M-D.png
 

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Discussion Starter · #7 ·
Gentlemen, thanks very much for your help and advice!
 
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