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5" ball shell with 1.75" inserts


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Posted (edited)

First insert shell, veline stars for the Saturn ring, ti dragon eggs and 4:1 mcrh for burst and d1 tail

 

6 veline star 1.75 shells with 4f as the burst

 

The ti dragon eggs wash out the first stars I think and it need a stronger burst, will try 7:1 on the next one

 

Unfortunately camera was a bit close so an insert was out of frame

post-23686-0-34051400-1644193924_thumb.jpg

Edited by Todd
Posted

Nice color stars.

 

Yes, burst is weak.

I have tried to use 1inch inserts in 4" shell and bursting charge as 7:1 MCRH and also used Home made 2FA BP. Had good results. Weak spread of stars due to weak bursting charge

 

How many layer of pasting done ? It will also affect the break to an extent.

 

What is the formula for DE that you have used ?

Posted

Brilliant start. Try to separate the effects by spreading the timing out a little so that the inserts go off after the ring burst has established itself.

Posted

Yes the timing of the inserts could be spread more I was worried about them comming back down to earth but after this I see that isn't an issue

 

Pasting was 4 layers with 75% overlap of 1" gummed tape, continuous method from pole to pole

 

De were bismuth trioxide + a few percent ti

 

Hoping more BP on the rice will help the next one, using Eastern red cedar charcoal milled for 7 hours

Posted
Typically plain corned or granulated BP will be used with round shells 3" and under. Rice hulls 4" through 12". Though there are better options for 8" and up.
Posted

Typically plain corned or granulated BP will be used with round shells 3" and under. Rice hulls 4" through 12". Though there are better options for 8" and up.

Maybe a little kick of dark AL. Neat trick I picked up here. Kinda kicks BP in the butt some :) 2-3% tops

Posted

Keep improving the pasting! More pasting helps with burst and lift (as the shell becomes a better fit in the tube less gas is wasted.

 

Beware copying formulae across country borders! Many chems available in one place are hard to get an exact replacement cheaply in another place. Sometimes using someone's formula and method simply doesn't work because of local availability of chems. Yes it's great to use the current best formula and method but sometimes it simply doesn't work.

Every published formulary is the best at the time of writing, half the formulae have been improved within ten years.

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