Kapok as filler?

[Ray B]

In older loading info I see Kapok listed as the filler for loads with excess powder space. In recent years I see Dacron listed. I'm wondering if the Kapok was replaced because Dacron was easier to obtain. Is there a qualitative difference between the two when using large capacity cases with cast bullets?

 

[7x57Joe]

Pretty sure that Dacron (polyester fiber fill) is easier to find and cheaper than Kapok. I haven't used any kapok but, have used a lot of polyester without any drama.

 

[AncientMariner]

Kapok is a natural fiber, so it isn't going to melt like synthetics are alleged to do. I've just begun tamping 1 grain of Kapok over a half-case of powder for an 8X60S Mauser. I noticed single digit velocity ES until the last round in the magazine. My guess is that recoil eventually dislodged the kapok wad, allowing the charge to behave as if the kapok weren't there. The other possibility is that the thrown, not weighed, powder charge was an "outlier." I was using the load for fire forming the brass to a slightly long chamber. I'm currently in the process of loading more forming loads with a touch more Alliant 2400.

 

[Ray B]

I found a mail order source for Kapok. Its name is Woolery and it is a store primarily for those interested in spinning wool into yarn, quilting and other needle craft activities. the kapok is sold in bulk 2 pound bags. Since the loading data that I have calls for 2 grains per load, that is 3500 loads per pound, 7000 loads per bag. The kapok is used in reduced loads for bolt rifles where the loading density is about 35% and for the 470NE full power loads with density 80%. I have not noticed any leakage of the powder around the kapok but I keep the cartridges base down after loading and they are fired with single loading. I haven't shot more than 20 at a time in one location and haven't noticed any residue in front of the muzzle so it appears the kapok is consumed in the firing. The bore needs cleaning after firing but I think most of the residue is powder soot. I haven't used 2400 in reduced loads. Back in the day I used Bullseye with a partial sheet of toilet paper to fireform cases for a 22/30-30AI.

 

[AncientMariner]

I'm not sure what it indicates, but with the Kapok wad in place, I was seeing velocities at the low end. Others have mentioned velocity gains. I plan to single load from now on. Shooting 139 grain bullets at 2100 fps is very pleasant. I got a one pound bag from Bean Products via Amazon. I first tried a local fabric shop. They'd never heard of Kapok. I blasted everything (barrel up, barrel down, normal handling, and with Kapok wad) into the same target, since I was curious only about extreme spreads and blowing the shoulder forward about 0.016." Next outing, I'm curious about accuracy. This rifle has a barrel wedge which may or may not have anything to do with the scattering of points of impact after the first few shots. I have heard of fire forming by filling the case with cream of wheat but the Kapok wad sounds safer to me. Besides, I read about it from my hero, Jack O'Connor.

 

[fourfive8]

Kapok seed pod fiber used for various filler purposes predates Dacron fiber by many years. So, when loads with filler were first developed, kapok was a likely or primary choice. Also at this time sheep's wool was also commonly used. One problem with many plant based fibers, like kapok or even cotton, is that they tend be hygroscopic. Another issue is they tend to not have a memory so will collapse into a lesser volume over time. These attributes are not good at all for any filler used in cartridges. Dacron is superior in every way and is widely available and inexpensive. Dacorn filler does not "melt" when used as a filler in proper smokeless loads.

Non-compressible, more dense fillers like COW, IMO, are not a good idea for use as a filler in reduced smokeless loads. Granular solids like COW should only be used as a total volume, non-compressible filler for use in some blackpowder cartridge loads. Low density volume filler and non-compressible filler wad are two completely different concepts with different purposes and consequence when used in cartridges.