Try something new

[Beekeeper]

OK,
I want to try using a filler (dacron) on some 8MM and 7.62x54R boolits but have (0) zero knowledge of how.
I have read the posts that I could find that talked about it and am (dense) just as confused as when I started.

Buckshot says to use a pinch, others say to use a gram or more.
Is there a set weight or size to use?
What type of dacron do I buy when I look like a fool in the sewing store?

I load the 7.63x54R with 13 gr red dot and the 8x57 with 15 gr of red dot.


Jim

[mooman76]

Dacron is just that fiber pillow stuffing, stuff. I use drier lint. Does they same and I have it available already and throw in away anyway too. I'm recycling.

[Dutchman]

Women in sewing stores love men who look like fools. Being comfortable looking like a fool is what endears women to some men. Embrace it.

Kapok is what I used in the stone age of my cast rifle bullet days (70s). I used 1.5 grs which is just a pinch.

But you don't need to use a filler for powders like Unique or Red Dot. Fact is, I don't use fillers for anything and I'm getting sub-moa _in_some_rifles_with_some_loads.

Dutch

[Bent Ramrod]

I use Kapok myself. Just enough to keep the powder at the bottom of the case; a piece as big around as the tip of your ring finger should be plenty. Tamp it down with a pencil. It should spread to grip the sides of the case but does not need to fill the case up. I never weigh the stuff.

It seems to help with powders like SR-4759 in the bigger cases. There's fewer half-burned grains sitting on the bottom of the rifle bore after the shot when I use Kapok filler, and fewer flyers on the target. I wouldn't bother using fillers with flake powders; they seem to burn completely in everything.

Kapok seems to burn completely. Never tried Dacron, but I have used cotton, and that seems to work also. By the way, a gram (~15.5 grains) of any of this stuff would fill up a huge volume, unless compressed down like a fiber wad. That would be way too much.

[beemer]

I use dacron in most of my milsurps with cast loads and 4198 at about 20-22grains, a half of a grain or a little less works fine. I fluff it up and push it in with a small wood dowel and let it expand in the case, I do not pack it down. I don't want a packed wad just a fluff to fill the space and hold the powder in place.

Please note that it is one half of a grain, not a gram.

Dave

[runfiverun]

and adding dacron to your fast powder won't gain you much.
it's already igniting fine.
you are in the 40-k range now with "the load" 13 grs red dot, and closer to 45k [maybe more]with the 15 gr loads.
filler is used to hold the powder aganst the primer for better [more consistent] ignition.
it also MUST touch the powder and the base of the boolit.
it is best used with the medium rate powders like 3031-4895.
it generally provides more consistent velocities [lower deviation].

if it's accuracy you are looking for, a change of velocity with another powder would be in order.
you are at the high end pressure wise and not close velocity wise.
i'd suggest a slower powder like 16-18 grs 2400 and possibly a pistol primer.
or 28 grs of 4895 and then the filler.
these loads are for gas checked boolits.
if you are using non gas checked boolits lower the velocity to 1400 or under.

[felix]

Very good, R5R, better yet, excellent! ... felix

[geargnasher]

R5R just condensed about half a lifetime of shooting knowledge into one post, very nice.

Beekeeper, if I could add, I would say that we are missing some critical information about what you're trying to accomplish with your loads. I feel that you're way off base with using such a large charge of fast powder, and I want to second-guess why you're wanting to use a filler at all for the sake of using a filler.

A filler is only a tool used carefully when needed to achieve something that is otherwise not possible or not practical. You have a multitute of excellent powder choices that will get you from mild to wild with either of those fine cartridges without fillers, and some that may work even better at the top end with a pinch of Dacron. I would try something like 4350 or slower with checked, heavy boolits, use what you would use for a comparable weight jacketed bullet.
If you want plinkers, use the Red Dot, but less of it, lots less. Unique is a whole lot better IMO. You can do some pretty impressive shooting in those big cartridges with a good load of Unique and a (ONE) grain tuft of Dacron fluffed into the case to fill the whole volume between the boolit and powder using NO gas check. The Dacron tends to act like a rope-type crankshaft seal in an engine or a propshaft stuffing box on a boat, it packs in behind the boolit and works in conjunction with the lube to make perfect bore obturation as well as sponge on a nice layer of lube.

One thing to keep in mind with any filler, they CAN and DO raise pressures somewhat because they effectively reduce case volume, so start small and work up each load, don't just add a filler to an existing safe load recipe or it might not be safe anymore.

Gear

[runfiverun]

thanks felix and gear.

another way to think about filler besides the above is as a case shrinker.
the filler also is like adding more powder at least it's own weights worth.
in the 28 gr load above one grain of straight up cotton towell dryer lint achieved the same results as adding TWO grains of powder.
in the tests little girl and i done two years ago with three same caliber different bbl length rifles the velocities went from a deviation of near 150 fps to right under 15 fps [airc] on average,
and shrank groups accordingly.
this was with bbls from 19" to 22" to 25", the loads were all the same chosen at random from the boxes.
all charges weighed, and fillers all weighed,all brass,powder and [win l.r. l.p and fed l.r. and l.p.]primers from the same lot.
we used 8 different powders [fast and slow pistol and medium speed and slow rifle] and two different cast boolits [plus one reduced jaxketed] and one copper tubing boolit i cut out and polished a mold for.
took most all summer. and little girl still won't shoot anything but the one [7.65 argie] rifle i built for her for the test.
anyways the whole thing bolied down to.
1. fast powders don't need nor benefit from fillers.
tipping them back and forth did change how they fired and sometimes forward was faster than at the primer.
2. medium powders did benefit from fillers if they filled the case less than 60 percent.
and often done much better even at or above the 60%.
3. slow for caliber or way too slow powder did thier best if under compression, but sometimes not enough pressure was achieved to completely burn all the powder.
4. i started to use some duplex powder loads but could see no benefit, and decided to abandon the tests.
5 some fillers do act as boolit protectors and can be used for high velocity application.
some are better than others and work better in older slope necked designs, and others do well with new case shapes but need a bit of compression to keep in touch with the boolit, and keep the powder from migrating into them.


now you all know what i know about fillers...

except that dog hair in the lint works better than cat hair does [ymmv]