Dacron filler

[AZ-JIM]

I see in reading several posts here that dacron is being used as a filler in cartridges. I'm guessing it's purpose is to keep light power charges against the primer in larger cartridges for more consistent ignition. I have two questions:

1) Dacron is polyester or a type of polyester, what form of it do you use and where do you get it?

2) Polyester is flamable right? So I can't imagine pushing a burnt, gooy plastic substance down the barrel being good for accuracy.

Can you shed some light on this for me? Thanks

az-jim

[littlejack]

I use the batting from the fabric store. It is used for filler in quilts and such.
I use it in my cast boolit loads for my 7.62x54. I cut a 1/2" or so square from the dacron.
I believe it is about 3/4" thick +/-. I poke it down with a 1/4" wooden dowel. I do not
compress it, just set it to the top of the powder charge. I try to transport my loads with the
boolits up, to keep the powder from migrating into the dacron.
Yes, it is used to keep the powder against the primer.
I have seen no significant fouling from the dacron. No gooey melt at all.
Jack

[runfiverun]

it just blows out the bbl.
don't pack it in there,use enough to hold the powder down.
make absolutely sure it touches both the powder and boolit base.

[Mk42gunner]

Research posts by Larry Gibson and Bruceb. The way they explain using dacron filler makes a lot of sense to me.

You can buy dacron or the generic equivelant at hobby stores, it is meant to stuff pillows and dolls and stuff like that. The entertaining but expensive way to get it is to have your young daughter leave her stuffed animals laying around for the new puppy to get hold of.

Robert

[crabo]

http://castboolits.gunloads.com/showthread.php?t=109280

[geargnasher]

it just blows out the bbl.
don't pack it in there,use enough to hold the powder down.
make absolutely sure it touches both the powder and boolit base.

I highlighted that because it seems that no matter how many times we say it somebody somewhere will still try to pack it in like Rosie's gut in a girdle, or pack a half grain down against the powder hard and leave an airspace between the filler and boolit base. High pressure will be caused by the first, the second causes ringed chambers from secondary pressure spikes due to the boolit acting as a barrel restriction to the flame front. And so Dacron has people scared, because somebody, somewhere, will screw it up.

Powder migration. I copied a test by another member here once. Take a fired case from the caliber in which you're wanting to use filler and cut a window in the side, from just above the case head to where the body meets the shoulder. Cover the window with a piece of clear plastic from a blister-pack or whatever, and tape it on with a wrap of clear packaging tape so you can see inside the case body. Put in your desired powder charge, fluff up 1/2 to 1 full grain of Dacron depending on the space to fill and poke it in the case so it puffs up to fill the gap loosely, contacting the powder and the boolit both. It should hold the powder in place, even if it is dropped. Now carry this round in your pocket for a few weeks and observe the migration. If you fluffed it properly, even a half- filled .30-'06 case should only need about 3/4 grain to keep the powder in place. You will be amazed how little it takes to prevent migration.

Gear

[HARRYMPOPE]

try "sill sealer" foam used in sealing the bottom plate of new construction from bugs
Schutzen guys have used it for years
i find it works very well if you decide you need to hold the powder back
you cut a disc of it a bit larger than the inside of the case and push it in with an appropriate sized rod to seat it over the powder
I used it in plainbase rifle loads for a year fillers didn't help my accuracy at all but it was easier to use than Dacron or kapok
HMP

[303Guy]

"sill sealer" foamJust be careful of transposing straight walled case practices to bottleneck cases. Dacron works fine in bottleneck cases as does cottonwool but cottonwool can and does sometimes burn and can start bush or grass fires.

I've taken to using wheat bran as a filler over reduced slow powder charges (65% load density) and found it to raise pressure to almost a nornal level for that powder. It also forms a wad under the plain based boolit. It's behaviour is not the same as dacron. With dacron there is no apparent rise in pressure and it is more suited to faster powders in larger cases.

[44man]

I like the garnetted fiberfill from Jo-Anne Fabrics. There are no long, thick, stringy pieces to fool with.
I have picked up a bunch in front of my bench and it is just a little dirty, never burned or melted. It could be used again.

[1Shirt]

A little goes a long way, like dac filler in most of the med burn range powders for rifle, from 2400 up. Ya, I know some will say that ya don't need it fro 2400, but it works for me, particularly well in 45-70. Been using it for years.
1Shirt!:coffee:

[gnoahhh]

Another alternative is the kapok found in old life preservers. One life preserver= a lifetime of cartridge filling.

[Jim]

http://www.castpics.net/subsite2/HowTo/Kapok.pdf

[AZ-JIM]

Thanks for the responses, very helpfull info. If anyone else has anything to add please feel free.

az-jim

[HARRYMPOPE]

Just be careful of transposing straight walled case practices to bottleneck cases.

I fired a a few 1000 rounds with it with no problems .I have used it for 6 years in calibers form 375 H&H down to 22-250 with no I'll effects.But i was using fast powders not medium or slow stuff.it never improved accuracy an meaningful amount to warrant the extra step so i abandoned it.

HMP