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Help! Need general specs for 3" bag mine!


jwitt

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Wow...been really busy lately working up my second batch of shells. I should have some leftover stars and a bit of BP left after finishing the shells, so I was thinking of making some bag mines as a last-minute project once the shells are done.

 

So I can get in the ballpark of a properly functioning mine, roughly how much good stuff should I put in each one? Similar lift and star load to a 3" shell, or more lift to account for the fact that I'm not launching a nice round object out of the gun?

 

Any advice would be appreciated- I understand that it's impossible to give precise info on this, but a starting point would be great.

 

P.S. we should have video of the 35 shells on the 31st of July...crossing my fingers.

Edited by jwitt
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I generally use 10% lift of 4FA on mines to really punch them up there. I'd say 100-125g of stars/inserts is my normal load. It's hard to tell really. I don't make them much for show, rather to test stars or get rid of extras. I also use lift pistons. Two disks with a wad of news paper and a center hole in between them.
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Alright, thanks!

 

Mumbles- how much of your lift do you use to lift a typical shell? (so I can convert over to my BP)

 

I'm making some to 1) add a bit of material to the show and 2) get rid of extra stars. Hopefully I'll have enough BP to make several, but if not I already have about 500-700g of fines from granulating a batch, all ready to re-wet and granulate.

 

Roommate is building a 5 shot rack and a 3 shot fan- he's not too into pyro like he should be (metalhead!) but he's an engineer, so I showed him the good rack designs and had him set about calculating the angles to set up the fan. Also had him draw and make templates for lift cup parts, and he'll be cutting paper products for those. Ahh, teamwork!

 

I'd like to have more guns, but I don't think my friends have any consumer stuff (though I told 'em to go grab some after the 4th) so a slowly reloaded show will stretch out for quite a while. I've got a nice finale planned- paced red-white-blue, then 2 50g salutes, then 2 simultaneous red & blue mix shells out of the fan followed by a big salute out of its middle tube. OK so it might be laughable to experienced pyros, but it's gonna be fun- gotta start somewhere B)

 

Never made it to my 100 shell mark, but after this shoot, I'll have put about 50 up, with only one failed so far (poorly attached BM on the spolette)! Man am I ever looking forward to making stars in fall (generally cool and somewhat humid), shooting a few for new year's, and then building shells the following spring for next year! It will be nice to not have to rush anything, and have all this experience I've gained in the last 6 months to build upon.

Edited by jwitt
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We made a slew of 3" mines two weeks ago. I will try to get the particulars but the gent weighing out powder measured out 50 grams to lift them. We were also using perforated disks with 1" sections of 1/4" spolette tube separating the two disks.

 

I was pulling the black match apart so we could thread it through the tubes so that both the lift and the stars could take fire at the same time.

 

I think a full cup of stars were used and were dumped into a loosely formed canister that was rolled up using the disk set. The end with the stars was tied up with twine, flipped over, the lift was placed in the bottom with the leader, the leader was taped to the side of the shell and an over-wrap of thin kraft was tied off at both ends leaving the leader pocking out of the top of the shell.

 

The comets were done exactly the same way.

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I use approximately 1/16th plus a little more by weight of the shell for lift. About what I would for commercial 2FA. I start with 1/16th and usually round up to the nearest ounce or half ounce.

 

I shot a couple of mines tonight. 10% 4FA-ish equivalent. My 4" mines probably made it to 100-150ft. It's hard to tell when you're directly underneath them, and being pummeled my sparks. 20g of lift for 200g of brocade stars with a lift piston.

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  • 2 weeks later...

Well, I made a couple mines, and they worked great. Didn't have time to make pistons, so I threw a disc w/ holes on top of the powder and a solid disk on top before pleating the top paper. I used enough BP to get those stars pretty high. The shot put the hurt on one ear. (Smart guy that I am, earplugs were in my pocket from earlier that day). Oh, I went out on a wing and crammed 300g stars in the mine. :D Worked nicely.

 

I hope I can find a pic/vid. It was...brilliant, so say the least. The crowd thought it was an accident, but we ran 2-way radios, so I had my roommate who was back with the masses explain the "shotgun shell."

 

After seeing how cool this was, I'm going to take the time to do things right when I make more mines.

Edited by jwitt
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