burst and lift for shells

[pyroaddict]

I am trying to figure out a chart for the amount of lift and burst for color shells. Say a 3" ball shell. I have heard that you need 1 oz of lift per pound of shell weight. Is this a good guidline? I have not found much information on how much bp to use for the burst charge however.

[Xtreme Pyro]

That ounce per pound rule of thumb was actually more for cylinder shells (someone correct me if i'm wrong). For 3" ball shells most people use 10% the shells weight for lift. As far as burst goes, just put as much as you can in. I usually fill my hemis just over the center line with burst, so that after the shell is closed your stars will not move around.

[pyroman2498]

As I was typing this my power we out about 5 times, as XP said to you 10% weight of your shells is fine ( in bigger shells and In larger can shells you use the 1 to 1 1\2 Oz of lift per pound) and as for burst full em' up! The more bursts the the better, just don't put so much in that even with tapping with a dowel it won't close . Edited June 10, 2013 by pyroman2498

[pyroman2498]

So many spelling errors due to spell check and auto correct sorry about that I'm on my phone :/

[Blackthumb]

I lift my 3" ball shells with 35-38 g of 3f BP

[Xtreme Pyro]

I lift my 3" ball shells with 35-38 g of 3f BP

 

That seems like a bit much blackthumb.. How much do your shells weigh? I generally use about 15.

Edited June 10, 2013 by Xtreme Pyro

[marks265]

For lift:

 

A couple of things are already covered here. One comment that I would like to add is the strength of your powder. There are more variations to lift powder than you can shake a mortar at. Like X Pyro mentions above you can go with half the amount of what others use and others, it seems go, go over an ounce. You could say:

 

15g because you have good powder 36g because you have bad powder.

15g because I want it lower and 36g 'cause I want it higher.

15g because I have a type B personality and 36g because I have a type A personality

15g because I don't want the neighbors to see and 36g because I want everyone to see

 

To come up with a chart based on other peoples responses is really asking to shoot yourself in the foot. Make your own chart for what you do with what you have. It is OK to get a starting point for any given shell but after that decide what you want to do based on responses from others as well as yourself. You will be taking some time to make the chart but look at all the fun you'll have!

 

For 3" shell burst:

 

This is a big can of worms based on how you paste a shell and what you stuff in it and what materials you use and how big your stars are and how heavy your stars are and what carrier media you use and how much of which break charge you use and did I mention when you get into shells that have more than 1 petal things may change a bit. Just a thought I had

 

You will have a lot of fun experimenting as you go is my point. Just take good notes of what you do and you will have your chart soon enough.

 

Cheers

 

Mark

[nesc39]

Shimzu recommends 35g of burst for a 3" shell and to use 9mm stars. This is taken from his book FAST.