Waiting for powder. What should I expect?

[i_r_machinist]

 I've made and shot a couple of 2.75" bore X 40" long cannons since about 1989. Always had a blast (literally).  I shoot a 2 lbs projectile (various) with 2 oz of 3f Goex powder. My Powder Master has left me for the great beyond (RIP Larry Gauger). My powder supply has dwindled, and my powder dealer has quit handling powder. I did a bunch of research and bought  some cannon powder from Jacks Powder Keg in Louisiana.
 My old barrels are DOM seamless .625" wall thickness steel tubing with press fit breach plug, pinned, welded, 85kpsi barrels. The newest one is even better.
Is this powder going to be the old "pee gravel" powder that I have to increase the charge for?
I will start with a light load, but would appreciate some insight.
Thanks from Dublin Texas
i_r_machinist

[buzz36]

witch grade you buy 1f or 2f or 3f
If you have no powder the sound you hear is silence
I know the coarser it is the slower it burns but  i would be interested in hear on any  change in tube pressure
i think a slower boom would be less pressure??? just my guess
I'm pretty much still new with my cannons but getting smarter all the time

[rmagill]

   I've been buying from Jack's for several years and their powder is Goex unless the judge told you otherwise. The cannon grade is quite a bit coarser than fg. I've bought from cannon to 3f from them and it's always been a good price and shipped right away.
Bob

[Double D]

For a bore that large you might want use Cannon grade powder, Fg at the finest.  You don't want 3f in large bore cannon, to much pressure.. 

Mat Switlik did some pressure gun work some years ago  comparing Cannon Grade and Fg.  There was a 40% increase in pressure with no difference on velocity.  I imagine there will be an even greater increase in pressure with FFFG. 

Take a look at our post at the top of the board called safe loads and construction.  Some good information.

For safety purpose absent any other credible source we point to the Safety guidelines of the N-SSA and AAA for safe construction of cannons.  One of the guidelines is that minimum wall thickness over the breech should be no less than 1 caliber.  2.75 bore calls for 2.75 inc thick walls.

Which pre 1899 cannon have you replicated?

[Cat Whisperer]

Good points, Douglas.

Quick rule of thumb:

The finer the powder the higher the PRESSURE.
The greater the AMOUNT of powder the greater the ENERGY, hence the greater the range.
Use the coarsest powder available to keep pressure low, and use the correct amount.

And of course Thickness of walls around powder chamber >= diameter of powder chamber.
If less you will someday find out it wasn't enough.

[i_r_machinist]

 I make a variation of a twin beam carriage mountain howitzer. All steel construction except for the wheels I bought from Hansen on this last one. I'll post pic tonight.
 I read the rules on barrel thickness over breech. I guess if someone wants one of my guns to shoot at a sanctioned event, I'll have to do some re-designing. Am I interpreting the rules right? If your barrel doesn't meet the specs of wall thickness, you can put a 3/8" thick walled core in it and you are good to go? 
 Oh, I didn't say I was OUT of powder, just down to a couple of pounds.
have fun
i_r_

[Double D]

I make a variation of a twin beam carriage mountain howitzer. All steel construction except for the wheels I bought from Hansen on this last one. I'll post pic tonight.
 I read the rules on barrel thickness over breech. I guess if someone wants one of my guns to shoot at a sanctioned event, I'll have to do some re-designing. Am I interpreting the rules right? If your barrel doesn't meet the specs of wall thickness, you can put a 3/8" thick walled core in it and you are good to go? 
 Oh, I didn't say I was OUT of powder, just down to a couple of pounds.
have fun
i_r_

No that is not correct.  The liner is for all non steel and non bronze guns, and for all steel and bronze guns that do not pass inspection.  The one caliber wall thickness rule still stands. 

Absent any other standards you are sticking you neck way out  building cannons for other people not meeting these minimum standards.  It is published credible standards you can point to, too show your intent to build a safe cannon. 

You should review the standards for the breech plug placement in the liner also.

With a few exceptions any  pre 1898 cannon you build will already meet these standards. 

[buzz36]

DD how are howizers done
is the N-SSA or AAA rule then  stand for the  powder chamber
the barrel i made and yet to fire has a1" wall aournd a 1" chamber  as the barrel is 3" wide but the bore is 1.7
GB size that leave the  walls appox 5/8"
dont think i ever shoot at one of ther shoots but i do understand and wantot be safe and meet the standards
 

[Double D]

DD how are howizers done
is the N-SSA or AAA rule then  stand for the  powder chamber
the barrel i made and yet to fire has a1" wall aournd a 1" chamber  as the barrel is 3" wide but the bore is 1.7
GB size that leave the  walls appox 5/8"
dont think i ever shoot at one of ther shoots but i do understand and wantot be safe and meet the standards

Howitzer and mortars use the powder chamber as the bore size.

The stickies cover all these detail and include links to the N-SSA and AAA websites.  You really should take the time to read these sites...lots of good info there.

[i_r_machinist]

Any future build will meet all AAA specs. I've ran SolidWorks simulations on this design of up to 65 KPSI with no breach distortion. Strangely enough, my breach plugs have exceeded AAA specs. This is the first cannon that I've allowed out of my control.
 

[little seacoast]

I like the tube and carriage you've made, should be darn near indestructible.  With that style carriage you could use the metal hubbed wheels that came later and are quite a bit less expensive.   

[jamesfrom180]

Little seacoast your right reminds me of the long Cecil

[i_r_machinist]

This powder is great!
http://www.youtube.com/watch?v=GIqF7uljtQU&feature=youtu.be
having fun
i_r_