Author Topic: Black Powder Load Question (Read 1136 times)

CAV Trooper · « **on:** December 03, 2004, 09:56:06 AM »

Hello all.

This is so cool...a board just for cannons.

It's great to find there really are other people like me out there .

I've been working with various black powder firearms for quite a few years but have only been doing cannon stuff for about a 1 1/2 years. I just finished a 14th century hand cannon with a 1" bore and am waiting for a Daniel King Howitzer with a 1.5" bore to be delivered from SBR. I'm also a gunner with the NPS at the Castillo de San Marcos in St. Augustine FL and shoot a French 6 pounder on weekends

After reading most of the posts on the board, I'm confused about powder loads. With rifles and pistols I've always used loads based on powder grains by volume. However, some of the information I've seen here talks about powder loads by weight.

I ran a test and found that 500 grains of 1f by volume just fills a 35mm film can. Cannon Mania's web site says this is 1oz (1300 grains) by weight. That's a pretty good charge. Which should I use when working up blank loads? Weight or volume? I have a good volume measure but don't have a scale. Also, what are your suggestions for good blank loads for a 1" and 1.5 inch tube?

Cat Whisperer · « **Reply #1 on:** December 03, 2004, 03:22:14 PM »

Trooper -
Welcome!

If you weigh it - it's accurate. Measurement by volume depends on the size of the granulation - which varies between brands and batches.

SO, weigh your charges. Or, use a volume measurement that you have VERIFIED for that batch of powder.

We'd love to see pictures of your handiwork! Post them or send them & we can post them.

Will Bison · « **Reply #2 on:** December 03, 2004, 04:12:55 PM »

I'll answer some of your questions.

Explosives are ALWAYS measured by weight. Volumetric measurement is an expedient once the weight has been determined. As an example, take your film canister and fill it with 4 or 5 f and weigh it. Then fill it with cannon grade and weigh it. You should observe a greater weight with the fine grained powder. The other variable is settling. Tap,tap, tap that film canister and watch the powder settle. Now you can put more powder in.

The film cannister is fine so long as you know what's in it by weight. Also realize that the Specific Density can change for several reasons, granulation and settling being the major factors. OK, let's move on.

There are 437.5 grains in one Avoirdupois ounce and 480.0 grains in a Troy ounce. A grain is a grain in either system. If you stick to grains you're OK. Normally we use Avoirdupois for weighing explosives so an ounce will be 437.5 grains, 7000 grains to the pound.

That film cannister should hold just a tad over an ounce and that's OK so long as you know what's what. ANY confusion regarding explosives is a reason to STOP doing what you are doing and get some help.

I'll list a few reference materials here. The titles are a bit odd sounding but I highly recommend them to anyone who uses explosives.

"The Blasters Handbook" I think it's still by DuPont.

"Blown to Bits in the Mine" ISBN 1-890437-14-X

"Elements of Ordnance" Copyright 1938 John Wiley & Sons, London: Chapman and Hall Ltd.

There is an old rule about explosives.

"Expose the minimum number of people to the minimum quantity of explosives for the minimum amount of time"

Be safe, have fun.

Cat Whisperer · « **Reply #3 on:** December 03, 2004, 04:36:07 PM »

Will -
Great explanation and sound advice. Well documented.
Thanks,

CAV Trooper · « **Reply #4 on:** December 03, 2004, 05:24:12 PM »

Thanks for the info guys. I had a feeling that Cannon Mania was a bit off. Where they show their full size cohorn mortar it says "3 ounces of powder (1300 grains = 1, 35mm film can)"

When all I could get into a 35mm can was about 500 grains, things just didn't add up. I've got an adjustable powder measure that I use with BP rifles and pistols. I'll throw a couple of charges and see what they come out to on a postage scale. I think it's pretty close to correct.

As soon as I get the digital camera recharged, I'll take a few shots of the "cannon on a stick" and try to post them. I'm going to try it out tomorrow. It should be loud as hell. :grin: SBR said my howitzer will be shipped next week. Can't wait.

BTW, I totally agree with Will and the "rules of explosives" EXCEPT when you're in combat. Then you change the word "minimum" to "maximum" and aim it at the bad guys.

Will Bison · « **Reply #5 on:** December 03, 2004, 07:18:33 PM »

Thank You for your comments CW.

Cav Trooper; I think you're gonna' like it here.

The phone rang and I wanted to add a few more comments. The books I mentioned are in addition to the various textworks already enumerated in the "sticky" section here.

"Blown to Bits in the Mine" is a great read. The author presented me with the original text prior to publication to proof for some of the technical accuracy. It's a history of explosives presented in a very interesting format. Very good section on black powder.

The "Blasters Handbook" is good particularly if you can find an older copy. I have a 1952 edition and the black powder section is noteworthy. Some of my newer ones don't cover BP as well.

"Elements of Ordnance", "A textbook for use of cadets of the United States Military Academy". "A revision of the Textbook of ordnance and gunnery by Col Earl McFarland". This one is over 700 pages of very technical stuff. The one thing I like about it is that much of it is applicable to ML cannons and black powder.

I've used several tubes from SBR and find them to be of excellent quality. In the last catalog that I got from SBR (15 years

), Paul talks about juice cans and chapstick tubes as a means of measuring powder. Hmmmmmm! I suppose that he and I will have to agree to disagree on that subject. I much prefer to have a good scale and from that develop a suitable measure.

Well, back to the Autocad for my next project.