I made a shell with hot BP - Man, what a surprisingly huge difference!

[Ubehage]

I want to start by apologizing for the lack of pictures and video.

 

Anyway, there was not much to see:

I packed a 2.5" ballshell with dragon eggs, and BP for burst. Really just to see how the hot BP performed, in comparison to what I used to work with.

 

Untill now, I have been making slow BP (I get that name now ), which has worked for me.

After getting the ballmill, I have been making some much better BP. Even when dampening the composition, I can both see and feel a difference in texture.

It somehow becomes "easier" to work with. And boy, does it also perform much better! I was surprised at how much of a difference it made!

 

The lift charge was 6% of the shell weight.

As I was packing it, I thought about how little BP was there. No way, this would work!

I was expecting a failure, and therefor I chose to take advantage of the season, and launch the shell right after a heavy rain. To protect against unwanted bush-fires (or whatever that is called in these climates).

 

As I said, I was in for a big surprise!

The shell went up at least 100 feet, propably more. I never expected that.

 

This batch of BP wasn't even ballmilled. Only the KNO3 was ballmilled, and the composition was screened through a 120#, and wetted with 20% water with 2% dextrin dissolved.

 

What I learned from this:

I need to work on attaching the lift to ballshells. The entire cup and all stayed in the tube, while the shell went up.

Edited September 20, 2015 by Ubehage

[schroedinger]

Ubehage it is normal that the cup remajns in the mortar.

 

The germans had a special system developped for this. In the bottom of the mortar was a gole formed like an ice cone. The lift got attached by using a quite heave cardbord ice cone. Now the shell was loaded with the cup sitting in the recess, fired and reloaded. This way the cones where forming a nice stack and could easly be dumped out after the show. Not of any real use today, since nearly no state allows reloading during a show today.

[stix]

I packed a 2.5" ballshell with dragon eggs, and BP for burst.

 

Just wondering if the dragons eggs would contribute to a bigger break?. ITIRS (I think I read somewhere) that dragon's eggs under pressure behave differently.

[Mumbles]

First, congratulations on stepping up your black powder. I think you'll find things will just work better now.

 

I quite dislike when lift cups stay in the gun. When firing from the same gun, build up can eventually lead to low breaks. This is a bigger issue at club shoots or public shoots, where multiple shells from multiple builders start to stack up. If it's just you, they tend to neatly host inside one another and become less of a problem.

 

I prefer no lift cup if I can. You lose some of the protection a lift cup provides, but you leave next to nothing behind. Doing this with cylinder shells is easy. You can use a lift wrap, or use pasted patches of paper known as a Jersey Patch or Jersey Finish. With ball shells, I tend to use the same concepts. The lift is placed into a baggy with the quickmatch and lightly secured to the shell with tape or something. If I'm not in a hurry, you can use pasted pieces of paper here too. If you are in a hurry, then aluminum tape works wonders. Both pasted paper and aluminum tape offer protection from sparks, embers, and debris still in the mortar.

 

I honestly haven't the slightest idea how dragon eggs perform under pressure. It's certainly a possibility however. Another possibility is that any prime you used on the eggs contributed to the burst. It's possible to totally fill a shell with stars and rely on just the the prime burning to open the shell. The increased burn rate of stars under pressure starts to become an issue with large shells. Several people have told me that a pretty substantial amount of comp can be consumed inside of shells just from the burst pressure. These would be 12-16" or larger shells. Not exactly an every day issue.