4'' lift charge problem

[whitepyro]

hey everyone
im about to carry out a test for lift charges on my 4'' shells by using dummy shells that weigh the same as a complete shell mine are about 350g - 380g after pasting . any recommended lift amounts in grams would be helpful before i carry out the test ,cheers

ps i used 100g last time and it wasnt enough

[NightHawkInLight]

The black powder you're using must be terrible. It should take an absolute max of 35g to lift a 380g shell. Mill the BP longer, use a better charcoal, granulate it. You are using a scale to measure your chemicals correct? Volumetric measuring would also be a cause of slow BP.

You can also improve how your shells lift by making them a closer fit in the mortar. In addition, confine the lift better. Add several layers of paper over it and it will reach a higher pressure in the gun. That will only help so much though.

[whitepyro]

i never tested that certain batch of powder because it was an emergency that i needed it.scales are crap yes but my willow charcole seemed to be the better choice of pine . Ive just fixed my mill so it should be better for the next batch after i get new scales. thanks for the info .

[pyros]

Hey there!

Under normal "one-break" 4" shells I use about 40g of lift, a little bit coarser then normal, I like a little bit more "volume" of powder grains under my shells, it's not so violent as fine one and gives a good consistent height that the bomb is going :)

[whitepyro]

ill see what my dummie test says with some decent powder.haha

[arial-shellz-R-US]

haha 100 grams... that would send a 4 inch shell to the moon... try 35-40 grams of GOOD BP

[whitepyro]

yeah its sorted now