aquired a barrel GB bore with a powder pocket some help please

[buzz36]

High the barrel i picked up is 1018 steel   bored at 1.71 that is 18"deep with a powder pocket 7/8x3" I still need to hone smooth the bore so that go up a little bit
never had a barrel with powder pocket can anyone tell me why it is so big in length and how one loads the powder bag in it Im thinking all i need is 200 to 400 grains would be my powder size range???
the powder chamber it tapered to the bore
thanks for any help  or suggestions
 
 

[Double D]

You have such a big chamber because the make of the mortar doesn't know what he is doing.

The total over all depth of the chamber  of a full size Federal pattern 24PDR-5.82" bore  Coehorn is only 4.25 inches. 

Scale that down to Golf  Ball scale the powder chamber would only be 1.3 inches deep.   

By the way,  cannons and mortars don't have pockets,  shirts and trouser do.  Mortars and cannons have chambers.  So if you see a maker saying his cannons or mortars have pockets let that be an additional clue that they don't know what they are doing .

[buzz36]

DD your right but i never had one with this chamber sounded very deep to me as well
I guessing  to save this barrel I should get the  chamber reduced and lengthen the bore alittle
 

[flagman1776]

 

[Double D]

You do not need a filler.  Forget it it will only complicate matters...do not worry about airspace.

You will not have enough airspace or a tightly enough fit projectile to set up the parameters to burst a barrel.  For the most the a lot of the air space issues are grossly exaggerated and old wives tales..

The minor amount of air space coupled the proper windage will make the whole argument irrelevant.

[jamesfrom180]

For clarity sake, is this a cannon barrel or mortar? 

[carmy53]

Buzz36,
Please post pics. We like pics.

[buzz36]

heres a pic of my barrel in question  its 25" long the chamber is 7/8"x3"deep I'm thinking  this chamber should be like 1" deep not counting the tapper would be much better i  not liking the idea making my powder bags with  lots of filler or the idea of  an air pocket between the  charge and the ball I will mostly be shooting golf balls but i might  choose shoot lead/zink as well

[flagman1776]

 

[buzz36]

i  made up a powder bag and can load it easy enouf  i used a copper pipe and a fitted dowell rod  inside the pipe insert the bag in the pipe and then put pipe down the bore and them push home the powder bag

[buzz36]

DD if i reading you right make my powder bag load it pack that and then fire and not worry 2"+/-  air space

[Ex 49'er]

i  made up a powder bag and can load it easy enouf  i used a copper pipe and a fitted dowell rod  inside the pipe insert the bag in the pipe and then put pipe down the bore and them push home the powder bag

This is the method I like to use, too.

[flagman1776]

The gentlemen above load exactly as I intend to do as a handle to grasp when removing the formed foil.

[Double D]

DD if i reading you right make my powder bag load it pack that and then fire and not worry 2"+/-  air space

That's right.

[flagman1776]

I have been making a mandrel for my chamber which seems very near your dimensions. 

[Zulu]

I used to drill a hole through the middle of my mandrel so I could blow on it and push the foil off the mandrel.  Otherwise, the foil wanted to collaspe through suction when I tried to pull it off.
Zulu

[buzz36]

Thanks guys and DD the carriage and wheels will be my winter prodject
I was so fearful of the air space between the load and the golf ball
 

[little seacoast]

Glad you got the info you needed, a little healthy fear is a good thing when it drives you to seek out answers to safety concerns. Fire in the hole!

[buzz36]

I  have only been  shooting my cannons  for  jsut about a year now and hooked onit sold most of my BP rifles keeping my one  flinter i realy like
I just like taking them to  the range for a day of noise and  giveing the other shooters something different to enjoy and i  met up with 3 other small cannon owners along the way and the  reinactors are hoping we get a shoot going one of these months
again thanks for all advice