Golf ball mortar - loading procedure & data

[Ratbelly]

I'm completely new to anything having to do with black powder.  I bought my mortar from an online company and I am very impressed with the quality and construction.  That being said, I'm not getting much of any help from the supplier as far as step by step loading procedure and what is a good starting point for the amount of black powder to use. 
 
He did recommend using FFg or 2F powder, and he told me that 250 grains will get the ball out about a half mile.  I'd really rather not start out at the max load (like with any loading).  Does anyone have a good starting point for say 100 yards or so? 
 
Also, he recommended putting the powder in, packing it with newspaper, then packing that with a damp newspaper.  For a cannon this size how big of a piece of paper should I use?  I thought a 1/4 page?  Is there something better to use than newspaper?  I did read somewhere you can cut cardboard circles to use also? 
 
Any help would be greatly appreciated. 

[Double D]

First welcome to out board , we are always glad to have folks join us.

Golf ball mortar huh.  Lots of folks start with one of these...notice I said start.  It is very easy to get hooked on theses things.  With the group of sponsors we have here they all make it very simple to stay  hooked.  They have a good selection small cannons to choose from. I hope you bought you mortar from one of them.  I can tell however from what you have posted that you probably didn't.

The reason I say that is that,  the advice you got from the manufacture is not the safe sane advice our sponsors would hand out.

FFg powder is a good choice for a properly constructed golf ball mortar.  250 grains with newspaper and especially wet newspaper, packed is not a sane load.  More on that later.

Why on earth would you want to shoot a golf ball 1/2 miles?  Dumb question, same reason why we have all tried it, to see if you can.  Go ahead and try but you will find it very frustrating.  Light of a big charge behind a golf ball and all you will see is smoke and fire.  The next time you will see the golf ball is if you happen to find it down range.  You will not see the ball leave the tube , you will not see the ball in flight and you will not see it land.

The furthest I have fired my GB mortar is just over 300 yards.  I did not see the ball leave the tube, I did not see it fly, I did not see it land.  I know it went 300 yards because that is were I found it. 

200 yards is about as far as I would want to shoot the GB mortar, with 100 yards much more enjoyable.   Also you will find if you have something to shoot at its a lot more fun.

At the recent cannon shoot here in Montana we had a hole in one contest. It was great fun. It was challenging and I think every one who shot it had a great time. Of course the $150 pot we had helped...no one got it and close didn't count.   I think you will enjoy shooting a GB mortar a lot more if you shoot it at something, instead of fling ball out out in the bushes.  Set a bucket out at 100 yards and see if you get ball in it. Great fun!

A powder chamber big enough to hold 250 grains is way to big.  30-35 grains of powder in my mortar will get 100 yards in my mortar.

Before we can help with suggestions for loads we need to know a little more about you mortar.  Where did you get it?  What is it made of .  Doe sit have a powder chamber, what are the dimensions of the barrel , particularly the diameter over the powder chamber. 

Pictures will also help...we like pictures here.

[flagman1776]

 

[Ratbelly]

I'll do my best to answer your questions.  I bought the mortar from cannonthunder.com  It does have a powder chamber but I don't have a way to measure it for depth or diameter.  I would guess there is a good inch of steel between the end of the mortar and the bottom of the powder chamber.

5" tall
3 1/2" wide at the base
3" wide at "business end"
bore is +-.060" under 1 3/4" diameter
4" deep with a tapered powder pocket
Fuse hole is 1/8"
weight is 12#'s
http://cannonthunder.com/GolfBallMortars.html

[flagman1776]

 

[Soot]

Cannon Thunder uses 4140 steel so it's pretty strong.
I had one a while back. I built a carriage for it and sold it.

[Double D]

The airspace issue is a commonly misunderstood myth and is not a serious issue in a blackpowder cannon or mortar.   You are not going have enough airspace in mortar  to be concerned.

[Ratbelly]

So what are the correct steps to loading the mortar?  I picked up some Triple 7 FFg powder last night.  What should I use for packing?  Old shop rags, cardboard, paper towels, newspaper?  How big of a piece would you say is sufficient?

I'm guessing you load the powder, place the packing and use a wooden dowel to pack it tight, then load the golf ball?  Maybe the first shot or two should be blanks?

What would be a good starting load size?  25 grains?  50 grains?

[little seacoast]

Keep it simple. Start with a small load, say 25grains, and forget about the packing or ramming the powder. A simple cardboard disk  of GB diameter can be used over the powder but isn't really necessary. On no account should you ram anything. Add a golf ball and insert a fuse of say 6 inches. Make very sure no one is in front of or behind the mortar and light it off. Repeat and adjust powder charge as needed. You do not want to send the ball into the next county.

[Ratbelly]

Simple sounds great to me, I'll report back when we finally make some smoke & noise.  Thanks a lot for everyones help. 

[Double D]

Triple 7 is not black powder. It is a smokeless powder substitute for black powder and has completely different burn, load and cleaning characteristics than black powder.  We don't recommend the use of the the substitute BP in cannons and mortars.

Most advice we give here is for black powder. 

You need to consult with the Triple 7 website to see what a Triple 7 equivalent load would be.

I have used Pyrodex with very poor results.  Pyrodex need toi be tightly patched to work and i don't know if the same can be said for Triple seven.

[Ratbelly]

Shoot, I wondered about that.  It seems like it's hard to find true black powder around here. I guess I'll have to pay up and order some.  Thanks for setting me straight.