Enough powder?...

[centermass]

I am going to try a live load soon and have a question....I have a 1 1/4"  bore and 20" deep. I am going to use a 1 1/4" steel ball and want to get some suggestions on amount of powder grains, the balls weigh about 8 oz or so, Any help would be great. Thanks!.........

[seacoastartillery]

     Most thoughtful folks will want to know how much windage you have between the ball size and the bore size BEFORE they will commit to a suggested starting load.  Have to know what granulation of powder you are shooting as well.  We believe you will be shooting a ball of 4 oz., not 8 oz. as stated.  What type of steel shot are you shooting.  Have you accurately measured a bunch to see if the sizes are consistent.

Regards,

T&M

[kappullen]

C'mass,

Dixie Gun used to have suggested powder charges for various bore sizes in their catalog.

Matt Switlick also has info in his book "The Complete Cannoneer" (paraphrase).

I used to use that, double charge, and double ball it for a proof test, metal stamp the proof charge,

and date done, and normal working charge on the trunnion end.

Be in a safe position during the proof operation. 

I have had carriages split during proofing so made a temperary carriage for that use.

It is good to mark a barrel because some day it may be in some one else's care.

This can save them injury, and you some liability.

You may want to start with a light load, and work up if worried about a blow up.

All this depends on the guns design, material, and workmanship.

This is my opinion, Take it, or not, is your option.

Kap Pullen

[centermass]

Thanks for the advice.........I have read alot on the powder charges and will study it more. Cool stuff...

[Double D]

You also need to check you bore and ball sizes, especially if using steels balls.  You are going need windage between bore and ball so the ball doesn't get stuck in the bore. If you stick a steel ball in the bore you are going have a very diffucult time getting it out.

If you look at the sticky at the top of this board called safe loads and cannon plans you will find the chart showing MAXIMUM loads for small cannons. The chart is from Switliks book, The more Complete Cannoneer. Switlik advice for starting load, start ridiculously low and work up.

[Victor3]

.....double charge, and double ball it for a proof test, metal stamp the proof charge,

and date done, and normal working charge on the trunnion end.

Be in a safe position during the proof operation. 

I have had carriages split during proofing so made a temperary carriage for that use.

Kap Pullen

 I'm not sure I'd want to "proof test" any barrel I was going to continue to use.

 It's my understanding that historically (at least with small arms), proof tested barrels were generally used to test a design above normal working loads, then scrapped. This would show that subsequent barrels made to the same design should be safe with the standard load.

 An overbuilt barrel (which as I understand it is the recommendation on this board) that has already been shown to be safe by design with a standard load should be 'proof' enough; I wouldn't think that stressing it by firing a heavier load would prove anything other than it withstood that one shot. It may even cause undetectable damage that could weaken it for the rest of its service life.

[Double D]

Agree totally with Victor...see my reply in the proof load post about the fallacy of double double proof loads

[Cat Whisperer]

Absolutely!

When the failure mode is catestrophic with no prior warning there is NO reason to push the cannon up towards that point by overloading it.

[kappullen]

.....double charge, and double ball it for a proof test, metal stamp the proof charge,

and date done, and normal working charge on the trunnion end.

Be in a safe position during the proof operation. 

I have had carriages split during proofing so made a temperary carriage for that use.

Kap Pullen

 I'm not sure I'd want to "proof test" any barrel I was going to continue to use.

 It's my understanding that historically (at least with small arms), proof tested barrels were generally used to test a design above normal working loads, then scrapped. This would show that subsequent barrels made to the same design should be safe with the standard load.

 An overbuilt barrel (which as I understand it is the recommendation on this board) that has already been shown to be safe by design with a standard load should be 'proof' enough; I wouldn't think that stressing it by firing a heavier load would prove anything other than it withstood that one shot. It may even cause undetectable damage that could weaken it for the rest of its service life.

I'd like to add that I wouldn't proof test any cast barrel in this way.

The great majority my creations have been machined, and bored from solid steel bar.

The bore sizes have been reduced due to powder, and lead costs today.

For example the 3# Light Brit gun bore was reduced from the full scale 2.937, to 2.375.

The 3# service charge used in 1776 was a pound, and I used a service charge of 1/3 pound.

My proof charge was still below the origional service charge using 1045 steel for the tube.

That is still conservative in my view.



Kap