BP calculations....?

[Klunk]

so anyway...

have a BP cannon that fires golfballs...

just got a mould that makes golfball size cannon balls out of lead

golfball is 1.58 ozs

lead golfball is 16 ozs

is there a simple calculation/ rule of thumb for devising a correct amount of BP to prevent carnage and mayhem?

or just pack er up and touch er off...?

 

[plinker 777]

...we start talking ounces instead of grains of powder I can only imagine. 1/8th pound? 1/16th? Where's your sense of adventure?

 

[Klunk]

Im talking weight of projectile....not powder...

 

[DEZ]

Is the cannon strong enough to handle the heavier lead ball ?

 

[cyclops666]

Golf ball cannon. I've got 2 five gallon pails of balls . I think I'll start drawing up the plans.

 

[plinker 777]

Im talking weight of projectile....not powder...

Yep, with such a heavy projectile 120 grains (of powder) probably won't cut the mustard...1/8 of a pound (4 ounces) of powder will get things "upwardly mobile"

 

[41 Colt]

I read on here a good way to measure is to poor powder over the ball until it is covers with a pyramid of powder, top and around the base too. I'm not sure how well this works.

 

[fingers284]

I use 1.5 " hardwood balls ( from Micheals craft store, $4 for 8) and cast steel mine balls in my cannon. It is aout .010" to small for a golf ball. I use 350 gr of Black for a charge. The wood balls weigh about 300 gr. and I havchrono'd them at 1200 fps. Willl go thru a 2x8 at 40 yrds with no problem.
The steelballs didn't register on the chrono but at 20 yrds they will almost go thru a 1/4" steel plate ( spits the steel where it hits but not enough to go thru).
With the wood there is very little recoil but with the steel it will roll the cannon back about 3 ft.

The tube is 34"long and .500 " wallthickness,it would be safe enough with more powder but I can get enough bark and smoke out of it with 350 gr and still afford to shoot it.

I don't know what the steel balls weigh but supose they are around 10 -12 oz..

 

[antiqueguy]

I read on here a good way to measure is to poor powder over the ball until it is covers with a pyramid of powder, top and around the base too. I'm not sure how well this works.

with real bp maybe but even that's pushing it with subs I can see a explosion happening and not the good kind

 

[Klunk]

Yep, with such a heavy projectile 120 grains (of powder) probably won't cut the mustard...1/8 of a pound (4 ounces) of powder will get things "upwardly mobile"

Im actually using the coffee measure scoop....I need to bring out the scale to find out what the actual charge weighs

it always amazes me how LITTLE powder it takes to make one hell of a boom if the projectile is tight/well patched

I certainly wont be using no 4oz of pyrodex....that's crazy talk!!

 

[plinker 777]

Where's your sense of adventure!?