Forums.NitroExpress.com

Mark,

I hope you would not mind my posting another response from Ka'imiloa which he sent you with a CC to me with a request that it be posted here:

Dear Mark,

I had a bit of time this morning and saw that you had posted my comments about your fine Braddell double rifle on NitroExpress.com. Thank you, and I hope they will be of some use to others too. Just before your post, I saw one from a fellow in Australia who suggested you alter your chambers to a groove-sized bullet. I don't think you need to do this, because a black powder with enough oomph like 1870s Curtis and Harvey #6 powder will turn your bullets into groove sized ones before they leave the chamber. Obturation is what was relied on in these old rifles, the same as factory Sharps ammunition.

Most nitro-for-black loads, from what I have read, do not have the rapid-peak chamber pressure generated by a good black powder and thus have trouble obturating bullets properly, especially many of today's commercial bullets turned out with harder alloys. Even a flat based pure lead (or perhaps very slightly hardened with tin for better casting, such as 1:50) bullet should obturate with a "hot" black powder like 1.5F or 2F Swiss or 2F KIK. No, not Elephant or Goex. Paper patching OR one or two vegetable fiber Walters Wads should prevent any leading problems, but use a good BLACK POWDER lube beneath and on your bullet if not using paper patch. If using PP, lube between wads, under the wrapped bullet, helps in softening fouling.

Your gun should, in my opinion, be strong enough to handle Triple 7 too, since it is about like Swiss 2F from what I have read. But whether it has the sharp initial peak to its pressure curve that "hot" black powder does would be the question. Again, instant obturation of your bullet is the key. I wouldn't worry about the clay plug in the base of the bullet. If you need to use it, a hollow based bullet will obturate better, just as the Minie bullets of old were made. However, it may be that the clay plug was to prevent the twisted base of a paper patch from lodging in the bullet's hollow base and possibly causing accuracy problems.

2F KIK black powder, now being imported to the U.S. from Europe once again I believe, seems to have a unique pressure curve which is very much like C&H #6, and it has been known to regulate BP double rifles when other BPs have not. Please keep in mind that we now have a bunch of BP and BP substitute powders to try, just as the smokeless loaders do, and that their peak pressures can vary by 30% or so. H-4198 smokeless often used now for nitro-for-black loading may actually generate LESS peak pressure than BP! (See Grame Wright's pressure records from the Birmingham proof house in his marvelous book Shooting British Double Rifles.) But remember that means the nitro load has to generate more AVERAGE pressure clear down the barrel than BP, in order to create higher velocity at the muzzle.

Again, I hope you will post these comments to the two BBs so they may be of use to others as well.

Aloha, Ka'imiloa

Best wishes and congratulations on your very fine rifle!

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The Ark was made by amateurs. Experts built the Titanic.

Mehul Kamdar