Safe load puzzle

[Millsman]

Puzzled, need direction as there seems to be disproportionate instructions over a safe load based on bore size.    I have a bronze cannon with a bore of 1 9/16th" overall length (not including the cascable knob) 21". Bore length of 19".Circumference at breech touch hole 11" at muzzle behind the swell 7".Weight of the barrel 43 pounds. I had a navel carriage constructed and a local smith did the iron work.  Have shown it to many cannon folks and no one seems able to determine if new or old.The trunnions are integral to the casting.  I use Goex Cannon Grade to fire salutes and given the sturdiness of the barrel I have in the past guesstimated how much powder to use.     Decided to be more careful this 4th of July and looked at the Topic: Safe Loads & Construction-NEW CANNON BUILDERS--DESIGN STANDARDS http://www.gboreloaded.com/forums/index.php/topic,89682.0.html?PHPSESSID=igvabe4ceg7hfb55a0tr068sd6   But regardless I must be misreading something in the Safe Loads directions below which first say use the chart http://www.fototime.com/90BD33C5013C58D/orig.jpg[/url] and so a  1 1/2 inch  bore cannon like mine should load 1 oz.   But while it says use the chart in reading through the following   Safe Loads
For guns under 2 inch use the chart below.
National Safety Rules and Procedures for Shooting Muzzleloading Artillery, as adapted by the American Artillery Association March 2000
1. Powder charges should not exceed 2 oz. of Fg or 3 oz. FFA or Cannon Grade Goex powder per inch of bore diameter. No excessive charges. Use black powder only.  So:  Based on the number 1. above it would appear that if I didn't use the chart but used bore size I could use 4 1/2 oz of powder (3oz for the inch and 1 1/2 oz for the additional 1/2 inch)    The extra 1/2 inch from 1 1/2 to 2 inches in bore adds up to a permissible additional 3 1/2 oz of powder and just  seems disproportionate to me.    I must be missing something.Your thoughts please. [/font]

[Double D]

Looks pretty simply to me.   The post says:
Safe Loads
For guns under 2 inch use the chart below.

So if you gun is under 2 inch go to the chart and look the load up.  There is only one chart. Use it. 

Now I do understand your confusion, since there is nothing that says the rest is  for guns 2 inch or over. Since it is my post i will fix it for you.  I guess I assumed  saying For guns under 2 inch use the chart below. was clear enough for folks with under 2 inch bores, that they would look at the chart below and skip the rest.

Safe Loads
For guns under 2 inch use the chart below.
National Safety Rules and Procedures for Shooting Muzzleloading Artillery, as adapted by the American Artillery Association March 2000
1. Powder charges should not exceed 2 oz. of Fg or 3 oz. FFA or Cannon Grade Goex powder per inch of bore diameter. No excessive charges. Use black powder only. 
2. Prepare powder charges in advance using heavy duty aluminum foil. Baggies may be used inside the foil, taking care not to allow excess air in the baggies and removing excess plastic where unnecessary.

N-SSA National Rules for Cannons
10.8.1 CHARGES
Maximum powder charges for all cannon shall be limited to that amount permitted by the chart as published below in Table 10.1. Only commercially manufactured black powder of American standard Fg granulation (150,000 granules per pound/ or 220 granules per 10 gr. wt. (avdp.) sample), or a coarser granulation, may be used. Charges must be wrapped in a powder “bag” fabricated of at least one complete layer of heavy-duty aluminum foil.

For specific load for you bore refer to N-SSA National Rules for Cannons Table 10.1. Page 71 of 194 in the PDF file.

Moderator note: For guns smaller than 2 inch THE MORE COMPLETE CANNONEER compiled Agreeably to the Regulations of the War Department as published in "Artillery Drill" by George Patten, 1861 and Containing Other Observations on Antique Cannon By M.C. Switlik with selected excerpts from other artillery manuals Appendix I has a load chart which is posted here by permission of the author.



To see a large view of this chart click on this link: http://www.fototime.com/90BD33C5013C58D/orig.jpg

This load chart is maximum load of a unpatched ball attached to a sabot.

 Addendum For mortars and howitzers the diameter of the powder chamber is the considered the bore diameter.

Both Associations recommend for safety reasons that larger caliber cannons not be loaded with loose powder, instead use foil wrapped cartridges.  Some locales have safety regulations requiring the use of foil wrap cartridges.  Mortars generally are still loaded with loose powder, but check your local regulations to be sure.   Click on this link to be taken to the post on loading cannon cartridges

Making Cannon Cartridges 

[WindElevation]

Just a question, at the bottom of the chart it says, 1 ounce = 480 grains wt. Why are they using Troy ounce weight instead of Avoirdupois 1 pound/ 16 oz system of 437.5 grains per oz. ? Thanks Gary.

[Millsman]

At the risk of being a pain in the a** I was hoping that someone could explain that while the chart seems to presuppose that there are no cannons with bores less than 1/2 inch and no cannons with bores between 1 1/2 and 2 inches,neither of which is true, that no further questioning of this formula is to be allowed. More importantly, that why there would be a sixfold increase in the charge permitted between a theoretical cannon with a bore of  say 1 7/8" and a cannon with a 2" bore is not clear to me and that is why I posed the question. (The former restricted to 1oz and the latter up to 6oz) Basically I have a problem accepting two standards: 1. All cannons under 2 inches 2. All cannons over 2 inches. Can someone explain the rational for these two standards.Thanks.

[shred]

Both sets of data for the 2"-and-above are for cannon built to modern safety standards, including steel bore liners.

General Information The following safe shooting procedure presumes the crew is firing projectiles with a muzzleloading artillery piece made (or altered) to modern safety standards. [...] The bore should be lined with seamless steel tubing with a minimum 3/8-inch wall thickness and a yield strength of 85,000 psi or greater. The breechplug should be threaded and pinned; welded and pinned breechplugs can be equally strong but require expert installation by competent manufacturers. Sand cored bores are not recommended for shooting. The vent should be drilled in a threaded copper bolt similar to original cannon vent liners of the 1840-1865 period) in order to provide an unbroken passage through the casting and the liner, into the bore.

The 1/2" to 1-1/2" data is very likely not, thus the discrepancy.  Non-modern-construction = use the reduced loads.

Perhaps this needs to be called out in the FAQ too-- especially the bit about the 2"+ loads designed for modern-constructed cannon and not any random cannon-shaped-object.

[Double D]

Just a question, at the bottom of the chart it says, 1 ounce = 480 grains wt. Why are they using Troy ounce weight instead of Avoirdupois 1 pound/ 16 oz system of 437.5 grains per oz. ? Thanks Gary.

Avoirdupois, the the typo has been noted many times in the past and will be corrected in next edition o f the More Complete Artilleryman.

[Double D]

At the risk of being a pain in the a** I was hoping that someone could explain that while the chart seems to presuppose that there are no cannons with bores less than 1/2 inch and no cannons with bores between 1 1/2 and 2 inches,neither of which is true, that no further questioning of this formula is to be allowed. More importantly, that why there would be a sixfold increase in the charge permitted between a theoretical cannon with a bore of  say 1 7/8" and a cannon with a 2" bore is not clear to me and that is why I posed the question. (The former restricted to 1oz and the latter up to 6oz) Basically I have a problem accepting two standards: 1. All cannons under 2 inches 2. All cannons over 2 inches. Can someone explain the rational for these two standards.Thanks.

It sounds like to me that all you want to do is find points to argue and nothing more.  You are reading things into this that don't exist and making the points up as you go.  You are correct the data for under 2 inch is not all inclusive. We don't pretend it is.

The chart covers .5" to 1.5" caliber it does not presuppose there are no cannons larger or smaller. It simply covers only that range,  nothing more nothing less.   

I am not going too change the post  to say for guns .5" to 1.5" caliber see chart below, because you are unable to comprehend the chart.

Your 1 9/16th bore is close enough to 1.5" bore to use the 1.5" data. (1.5 vs. 1.565).  Keep in mind that these are maximum loads and intended for Cannon grade blackpowder.  Follow the guidelines suggested The  More Complete Artilleryman and reduce your charge by starting ridiculously low and work up.

FWIW if you do an extension of the graph and extend the trajectory of the graph line from 300 grains to 500 grains to two inches the line come out right around 2 oz per inch.

If you have any questions about how the chart is formulated I suggest you direct them the author  of The More Complete Artilleryman.

I am afraid, I must demonstrate one more element of or shoddy work here,  these load recommendations are not for blank shooters, they are for  shooting projectiles. 

[Double D]

Both sets of data for the 2"-and-above are for cannon built to modern safety standards, including steel bore liners.

General Information The following safe shooting procedure presumes the crew is firing projectiles with a muzzleloading artillery piece made (or altered) to modern safety standards. [...] The bore should be lined with seamless steel tubing with a minimum 3/8-inch wall thickness and a yield strength of 85,000 psi or greater. The breechplug should be threaded and pinned; welded and pinned breechplugs can be equally strong but require expert installation by competent manufacturers. Sand cored bores are not recommended for shooting. The vent should be drilled in a threaded copper bolt similar to original cannon vent liners of the 1840-1865 period) in order to provide an unbroken passage through the casting and the liner, into the bore.

The 1/2" to 1-1/2" data is very likely not, thus the discrepancy.  Non-modern-construction = use the reduced loads.

Perhaps this needs to be called out in the FAQ too-- especially the bit about the 2"+ loads designed for modern-constructed cannon and not any random cannon-shaped-object.

Read the entire safe loads and cannon construction post, it all there.