2 FA Powder load for 1" cannon

[Rocky-77]

I've been making and shooting fireworks for years but am a newbie when it comes to cannons. I have a 1" bore naval cannon on order and am curious on how much 2FA black (blasting) powder to use in it. There seems to be a lot of conflicting information on the net about loads. 2FA is much coarser than 2FG so I would imagine more could be used.  Also, why are grains and drahms still used rather than grams when listing cannon loads? A gram is always a gram, but a grain could be 60-65mg...lots of room for variance. I plan on using this for noise only and would appreciate any guidance someone could provide. I'm guessing about 15-45 grams.

Thanks

 

[rsilvers]

Grains by weight are always the same - 7000 to a lb.


Grains by volume - you can ignore that, and use grains by weight if you want - but once you have a load figured out it is easier to go by volume.

[Delkal]

A gram is ALWAYS  15.432 grains.  It doesn't matter what powder you are weighing.

A dram is ALWAYS 1/16 of an ounce (27.34 grains)   No modern references one uses this anymore.

Dram Equivalents on Shotgun shells is the amount of smokeless powder it takes to give the same velocity as a given black powder load.   A 3 dram equivalent load means their smokeless load will give the same velocity as a shell loaded with 3 drams (82 grains)  of black powder.  Other than comparing the obtained velocity there is no meaning to it.

Most powder measures for black powder rifles and pistols are based on Volume.  If your flask has a tube to deliver 30 grains this is approximate.  Usually this is close enough for shooting but it will vary between powders. 

[GGaskill]

... why are grains and drahms still used rather than grams when listing cannon loads? A gram is always a gram, but a grain could be 60-65mg...lots of room for variance.

I assume we don't use grams because there is no history of using grams for non-scientific measurements in the US.  All reloading data is given in grains (at 7000 to the avoirdupois pound); both for bullets and for powder charges.  A grain is 64.8 mg by the math.

One is neither better nor worse than the other; it is just the convention.  Sticking to the convention reduces confusion.

[ironball]

Grams? This is the good ole USA, we don't need no stinkin metric system. LOL.

[Delkal]

Grams? This is the good ole USA, we don't need no stinkin metric system. LOL.

Grains are much better for shooting.  For my pistol rounds would you want to weigh out 0.006857 ounces (or 3 grains)  Bullseye powder.  Vs 0.008000 ounces for a hot 3.5 grain load?

Also if you said you used a 8 1/2 dram load in your cannon.   What is 8 1/2 divided by 16 ( to give ounces) and what fraction of an ounce should I weigh out and load?

[cannonmn]

I've never heard anyone recommend using 2FA for shooting projectiles.  That powder is chemically different from potassium-nitrate-based blackpowder we use in cannons.  The grains are very large but it does work for a firework mortar lift charge.  I'm sure it isn't dangerous to use in cannons in good condition except that you could have a lot of it going out the muzzle unburned.   I have heard of reenactors using it for blank loads but I don't know how well it did at that.  I tried it in a thundermug with a 2" bore and got rained on by unburned grains after each shot.

[gunsonwheels]

by cannonmn:
 

I've never heard anyone recommend using 2FA for shooting projectiles.  That powder is chemically different from potassium-nitrate-based blackpowder we use in cannons.

I don't think this is correct.  I have the data sheets from DuPont circa 1970 and they show Fa and Fg are chemically identical to each other.  I need to buy a scanner and then I could post them.  Both are Potassium Nitrate based powders with 4Fa being fairly equivalent in composition, density and granaulation to Fg.  Back then they also produced "B" blasting (Fb) powder which is a sodium nitrate based powder and as the NaNO3 is more resistent to giving up its oxygen it is hence less potent and slower getting going.  At that time "B" was $.64 a pound in 50# boxes and "A" blasting was $.86 a pound in the same packaging.
 
In recent years "B" was dropped as NH4NO3 (Ammonium Nitrate) became the slow moving blasting agent of preference but "A" continued in the same granulations, composition and densisties as it always was but was also dubbed "Fireworks Powder".  GOEX's data sheets replicate DuPonts in every detail that I can find... including using differing units for the densities... but after converting the units it all works out.
 
The only real difference I have been able to detect is "A" blasting is not as precisely controlled from batch to batch as the Fg series.  But both changing lot numbers on cases and cans requires re-acquiring or adjusting your load to achieve the performance of a previous lot number.
 
I use Fa exclusively as I still don't feel I can afford the sporting Fg series stuff...
 
GOW 

[rmagill]

How much difference is there in the price  between Fa and Fg ? Is it available at the same places or is it a speciality item?
Bob

[gunsonwheels]

Well there surely isn't as much difference as it was in the 70's.  Fg was trading around $3.95 a can but that was in a retail sporting goods outlet.  The last Fa I bought was $10 a pound in 50# cases and the last 25# bag of Fg I bought was $12 a pound.  Bear River Powder in Wyoming could give you an update if there is one:
 
http://www.bearriverpowder@allwest.net
 
Other powder distributors should be in the same ball-park for price but with added shipping and haz-mat fees.  The shippers won't carry the stuff if it isn't in cans so for the cases and bags that requires the buyer to come up with his own shipping containers (I use 20mm ammo cans) so I usually make the drive to Evanston and pick it up personally.   A case of one pound cans of Fg, of course, are a couple bucks more per pound.  Track-of the-wolf also does internet sales and are reasonable but not the cheapest.  Craig at Bear River is an avid shooter of ordnance as well as a GOEX master distributor and also has a manufacturer's license so if you can talk to him he is a wealth of information.
 
Good luck!
 
GOW

[Rocky-77]

Thanks for the history of why grains/drahms are still used.....I look at the metric system using grams as much more accurate and less room for errors. FA black powder is just a coarser granulation system for grading black powder made from potassium nitrate.
However, no one answered my original question on load size for a 1inch bore cannon? If no one's familiar with FA grades, how about loads using 1Fg grade black powder?
Thanks

[GGaskill]

If you look in the sticky called "Safe Loads & Construction-NEW CANNON BUILDERS--DESIGN STANDARDS", near the bottom you will find a graph that gives Matt Switlik's recommendation for "... maximum load{s} of a unpatched ball attached to a sabot."  It shows 180 grains for a 1" bore.

[smokemjoe]

  2fA , works great in my bowling ball mortar, I use up to 4 oz., $7.00 a lb.