case filler size & shape

[rp85]

good morning;

Using a filler with a 283 grain gas check cast bullet and 35 grains of imr 3031 in a 375 Weatherby case. I know i‘m over thinking this but just trying to control a variable I can control, it’s the shape of filler.

Easy to have square or rectangle shape filler but does anyone use a round filler? if so how did you cut the filler into a round shape? Thx for any input.

rp

[mehavey]

I'd recommend not pursuing a case "filler," per se -- but rather a powder "positioner,"
A marble-sized loose tuft of either dacron (new school) or better, Kapok (old school)
poked into the case/down loosely against the powder is suggested.

[Larry Gibson]

If a sufficient size of Dacron (just enought to fill the space between powder and bullet base) is just poked into the case it will fluff out or expand to fill the air space. It doesn't matter if it was square, round or just a pinched off piece to begin with.

Neither Dacron or kapok or any other material should be bushed down onto the powder leaving a space between it and the gullet base as that is a "wad" not a fller.

[mehavey]

Neither Dacron or kapok or any other material should be bushed down
onto the powder leaving a space between it and the gullet base as that
is a "wad" not a filler.I have found (FWIW/YMMV *), that loose a "marble-sized " ½-grain/tuft of loose (not compacted) kapok
-- pressed into the case to contact the powder/hold it in place (still not compacted), is immediately blown
out of position with primer ignition, is a "soft" material as opposed to "wad-like", and is completely consumed
upon firing...

...and leaves no two-inch-long fuzzy caterpillars all over the place on the range ahead of the shooting bench.

* (IMHO) [smilie=f:

[centershot]

mehavey, many years ago I ringed the chamber of a really nice Winchester '94BB rifle by doing what you are doing. Be careful.

[mehavey]

(. . . not compacted )