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Black Powder ....which ?

I'll be doing my first dual deploy launch this weekend. While I could just borrow some black powder from someone at the launch I figured I should be more self sufficient and buy my own. I had remembered reading that 4F was what is considered best. Today I went to largest gun shop in my area and was told they didnt sell 4F powder but they did have 3F...so I bought it. The guy there said something about only being able to store 50 lbs so he said he doesnt carry it.

At any rate.... is 3F powder acceptable ? I think I remember reading that it was but not really sure. The guy at the gun store said I could take a couple pieces of 2x4 or mortar and pestle and make it finer....should I ? Also I was planning on using about a gram in each charge well. Should I use more if I use 3F ? Thanks for helping this newbie.

-John

Reply to
J.Hardy
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3F should work pretty similarly to 4F for ejection.

-dave w

Reply to
David Weinshenker

3F is fine. USR OEM specifies 3F for ejections.

AT uses 4F.

1 pound is a near lifetime supply for rocketeers.

Jerry

Reply to
Jerry Irvine

Does it weigh the same per volume? Should I use a bit more vs 4F?

Thanks

Reply to
J.Hardy

3F and 4F is fairly volumetrically equivelant. 3F burns a bit slower and is better for "ejections".

I believe AT (GCR) became fixated on 4F because his first motors were

18mm C sized composites where the sheer small size of the unit gives incentive to shift to 4F. But I have a 24mm/29mm/38mm perspective where 3F is superior.

Historical Jerry

Reply to
Jerry Irvine

"J.Hardy" wrote

I use FFg as I usually make tight fitting connections (or use shear pins) and a slower forming ejection gas suits my needs. FFFg is said to be in the range of -20+50 mesh and FFFFg, -40+100. The smaller the mesh the faster the burn, by making a powder out of your BP you run the risk of overpressureing the vessel.

Below is a list mesh to grade found on the web:

Sporting Powders:

-0.5+4 mesh Whaling

-6+12 mesh Cannon/Life Saving

-10+20 mesh Saluting

-12+15 mesh Fg

-16+30 mesh FFg

-20+50 mesh FFFg

-40+100 mesh FFFFg

Blasting Powders:

-0.3+5 mesh FA

-4+12 mesh 2FA

-10+16 mesh 3FA

-12+20 mesh 4FA

-20+50 mesh 5FA

-30+50 mesh 6FA

-40+100 mesh 7FA

Meal Powders:

-40 mesh Meal D

-100 mesh Meal F

-140 mesh Meal XF

Reply to
cat

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