I know this is an older thread but as a sometime filler user I just have to butt in.
A couple of the posts above refer to an overPOWDER wad.
Please don't do this if there is any air between the wad/check and the bullet.
It is a poorly documented but widely believed phenomena among the double rifle crowd
that ramming anything up into the mounted bullet under fire is asking for a ringed chamber.
I have ringed brass right at the base of the bullet doing this and immediately gave up.
Card or other wads that do not fill up ALL the airspace must be touching the bullet.
If you are not having any problems: great!
It's true the X-Frame is more than likely made of better steel than a vintage double, but please be vigilant.
My double is not vintage, made of modern steel, but I still won't be loading any more of those over powder wads.
That's where the fluffy buffers come in.
Grex has worked great for me and still does.
I thought it was polycarbonate but looked into it and see that it is indeed polyethylene.
http://winchester.com/SiteCollection...0SHOTSHELL.pdf
I got several bottles when I thought I was going to be making a bunch of high performance pheasant loads.
That didn't happen to the degree I had planned so I started experimenting with it in 44 target loads.
Unlike some buffers, it seems to just simply disappear.
The BPI buffer should perform the same.
BPI Original Design Buffer (500cc)-ballisticproducts.com
I don't know if it coats the barrel or not.
Pufflon does.
Pufflon: Ingredients and Ballistics
It is VERY finely ground (think dust) and contains Moly.
This affects following shots even if they are not buffered.
I gave up on it mostly because of the mess dealing with the fine powder and I am not a big Moly fan.
Styrofoam may not be the best material for a buffer with it's low melting point.
Getting the exact same amount in each case might be a problem for the OP using his home made method.
Guess no one is gonna really know until they try it!
I have used TP and it leaves an unholy mess of shredded paper out in front of you.
Indoor range owners are not going to be pleased.
Don't ask how I know this!
So for case fillers:
a) Try for the least mass. Every grain you add inside the case affects the final pressure and ballistics.
b) Fill up all the airspace plus some. You want some compression to hold the powder down and minimize mixing with the filler.
The double rifle folks who use fillers in those huge cases with modern powders usually go with dacron batting or foam plugs.
Foam plugs are used by Kynoch in all their Nitro-For-Black loads and several regular double rifle offerings.
Those wads are available here at the bottom of the page:
Trader Keith
A load I use in my B. Rizzini BR-550E 444 Marlin double rifle (and the Marlin 444S) is:
24 grains 2400, 13.5 grains SuperGrex, Sierra 240 JHC, any 444 brass, WLR.
This blows the case out well enough to provide a solid seal giving nice clean brass and 44 magnum carbine ballistics.
The lowest power yet accurate 44 load I ever developed is:
4.5 grains PB, 10 grains Grex, 240 SWC sized correctly, W-W 44 special brass, WLP
Other substances I have used without apparent pressure problems are used tumbling media.
The cobs are lighter and as such preferred over the walnut.
The walnut I am convinced if used regularly will polish your barrel!
You certainly won't have to clean it.
Might actually be too much of a good thing.
The smell is also different than anything else you might encounter at the gun range.
Think rock festival.
