One of the original CBA guys, ?Wayne??, from SE Mass. or RI, shot at Old Colony in the late 70s, early 80s. He told us that the CBA had gone through the filler routine and that fillers weren't needed. I was running a 45/70 Rolling Block at the time, and DuPont/IMR was not making SR4759, and I couldn't get Unique to shoot without a Dacron or TP wad-Dacron much better because the TP wouldn't stay down against the powder. ?Wayne? made me feel guilty, so I tried to find a Unique load that shot accurately without a wad, and couldn't -even when velocities began to hurt.
So I accepted the guilt, hung my head, and still use 14 Unique and a Dacron wad.
Then the “Dacron wads ring chambers” story began, many will explain that and how this works, yet examples of actual true cases of it happening are as rare as politicians telling the truth.
I mostly shoot SS rifles, and have found that IMR4227 and AA#9 are not position sensitive and work as well without as with fillers. (Cork or cardboard or plastic wad in the case mouth to hold the powder in while breech seating.) SR4759 works well with a Dacron wad, and equally as well with more powder and no wad. 19 and a wad, 22 and no wad give ~same accuracy.
Cream of Wheat works just fine in BP lower-powered cartridges. A slower more comfortable 45/70 load is 50/FFFg (some say FFg); but that leaves an air space in the case, and we have been warned about that. So, drop the Black Powder, drop the COW on top (seems to work as well with no card or ? wad between the powder and COW as with a wad, if the bullet mashes everything down. This is a nice less recoil accurate load, and it's clean. Prime with ~5 gr. of about any of the slower smokelesses and it's real clean.
This also works fine in 40/50 Sharps Straight, 38/55, 40/65 and other straight walled cases.
I've used COW fillers in 30/06, 30/30, 303 British, 30/40 ~ others because it was used in Krags 100 years ago; but recently there has been a lot of talk about COW forming a “hard clump” and maybe blowing the gun up. Again, real life examples are between rare and non-existant. Anyhow, the COW in bottlenecked cases never did anything worth continuing the use with the (maybe mythical) risk.
COW in low-medium velocity loads and unlubricated byllets leaves no leading. I've done this a lot, following Norm Johnson, trying to understand what lubes do.
When making 40-1 7/8 SS cases from 30/40? cases, I thought I'd blow the cases out by shooting a 30 cal lead bullet in the 40, and I did, and it blew the cases out wonderfully. However, the lead was impressive in the barrel. More than I've ever seen, the rifling was invisible. On advice, I loaded 40 cal bullets at low speed with COW over the powder, and a dozen shots cleaned the barrel. ?6 Unique?
I've used some plastic powder I got from the shotgun guys, maybe Grex but I don't know. Also used coffee, corn muffin mix, oatmeal (very light) and who knows what else.
Outside of the LV BP straight sided case loads such as 45/70, I've never had a filler such as COW make a more accurate load.
With Unique in big cases, 45/70 or 300 WM, and in 30/06 and 30/30 and others, a Dacron wad has generally helped accuracy. Standard 300 WM load was 17/Unique and Dacron and 311299.
But, some say Dacron causes ringed chambers.
Somebody gave me some kapok, it worked, but so does Dacron, and where do you get kapok? Some advocate cotton, but if you tamp the cotton down on the powder and then the cartridges get jostled in the motorcycle, the cotton comes up odff the powder. Dacron doesn't. TP does also. Somebody wrote about milkweed pod stuff, I used it, it worked, but it's embarassing. Paper towel, wads cut from a sheet of plastic foam, none of it worked better than Dacron-but the RISK!!!
Fillers are like COW, fill the case between powder and bullet base. Wads, like Dacron, to me, are teased balls of fluff as big as a dime/nickel, tamped down on the powder with a pencil eraser.
I think that one should avoid the use of wads and fillers, select the right powder and save the time and risk. IMR4227, AA#9 (some say #2), 5744 all seem to work without eads and fillers.