To add filler or not add filler, that is the question.

[rnhathaway]

How do I know if I can or should add some sort of filler to my cases(dacron)? Is there some rule of thumb? If it is determined that I do need it, Should I reduce my charge by the same amount so I don't get a pressure spike?

[curator]

Fillers are used for a couple of reasons. If the powder you are using is position sensitive or very slow burning rate, a filler can help with ballistic uniformity by keeping it back against the primer end of the case and taking up room. Granular fillers like plastic shot buffer or cream of wheat can allow you to shoot slightly under-bore size boolets with moderate accuracy instead of severe leading and key-holes on target. They may also allow you to shoot gas-check design boolits without checks afixed, or in rough, pitted, eroded bores. What they can't do is make a good load shoot better. All loads using filler need to be carefully worked up a little at a time watching for pressure signs.

[303Guy]

I have a tendency to use fillers routinely. Dacron as a powder positioner and wheat germ when I want to raise chamber pressure and to protect the boolit bases.

[Larry Gibson]

http://castboolits.gunloads.com/showthread.php?109280-The-proper-use-of-fillers

Read Post #2 in particular.

Larry Gibson

[303Guy]

Something to be aware of, polyester is not Dacron - Dacron is polyester. Other polyester fibres can be quite course in comparison to Dacron and probably won't work as well. Dacron has the consistency of cotton wool. It usually melts into a ball and disappears down range.

Don't use cotton wool - it can ignite and cause grass and bush fires. Not always and probably rarely but it can. Wool works just fine but does have a distinctive smell when fired. I got some wool wads from Jeff cut into suitable shotgun wad sizes.

[jonp]

http://castboolits.gunloads.com/showthread.php?109280-The-proper-use-of-fillers

Read Post #2 in particular.

Larry Gibson
Great post, Thanks.

[jonp]

"Something to be aware of, polyester is not Dacron - Dacron is polyester."

Indeed. Dacron is trademark name for Dupont used much like Kleenex, Saran Wrap or Windex.

[rnhathaway]

I'm loading a cast 55gr FN RCBS bullet over 18ish grns of RL-7(still working on the right load to get dependable cycling of my bolt). So from the post you referenced, dacron seems to for the bill for his definition of needing filler(medium burning powder, less than 80% fill and lighter bullet). He used 1/2gr for a .30 cal case, so how much should I start with in a .223?

Thanks.

[runfiverun]

you need enough to put pressure on the powder and to be slightly compressed by the boolit.
THE filler MUST touch BOTH the powder and the boolits base.

I go by volume not so much by weight but 1/2 gr should be enough.
don't pack it in there, but use enough and be consistent.

[Pilgrim]

You can weigh it (the filler) but that is slooow and a pain in the butt. Been there done that. The dacron is very light so there is no real need to weigh it. Take a pinch of the stuff, push it into the case and go from there. You will soon get the feel of how large "a pinch" is needed. You want enuf that when you push it into the case (down against the powder) that it expands and fills the neck of the case. Seat the boolit and go shoot it. As always, work your load up. Don't start with a max load and then add a filler. FWIW Pilgrim

[Larry Gibson]

I'm loading a cast 55gr FN RCBS bullet over 18ish grns of RL-7(still working on the right load to get dependable cycling of my bolt). So from the post you referenced, dacron seems to for the bill for his definition of needing filler(medium burning powder, less than 80% fill and lighter bullet). He used 1/2gr for a .30 cal case, so how much should I start with in a .223?

Thanks.

1/3 gr +/-. The idea is to use just enough to fill the air space between powder and the base of the bullet holding the powder in position. An exact weight is not critical but using the minimal volume to accomplich the task of holding the powder in place is. As mentioned a slight comression of the dacron filler by the base of the bullet when seated is good. An air space by too little dacron or by tamping the dacron down on the powder is potentially bad.

I also do not weigh the dacron but "eye ball" it as mentioned in the post.

Larry Gibson

[zomby woof]

I loaded some 3031 into a 30.06 in my early years of casting. There was delayed ignition. Click.......bang. That sucks. I now add Dacron to all my medium burning power loads, no more problems.

[Kraschenbirn]

I use a poly-fill quilt batting for filler. While it's not labeled as 'Dacron' it comes in 45"x60"x1/4" sheets and is approximately the same consistency as the genuine 'Dacron' pillow batting sold at the same fabric shop. For consistency, I've found that batting sheets are much easier to work with than 'bulk' stuff from old pillows. I cut mine into strips, then, snip individual squares from the strips, varying the size according to how much filler I need for a particular load.

Bill

[Char-Gar]

Over the years, we have had several "filler wars", on this board. There is a variety of opinions and experiences with the subject, and the holders of each one, swear it is the holy truth. I don't often use fillers and I have not found them to be necessary to achieve MOA accuracy in my rifles, therefore I head for the hills when the subject comes up.

By now!