My lifetime supply of filler was just delivered. The least I could by was a coil rope of a 100 feet, 5/8th inch(.625)open cell foam. The entire box cost me $15.95. This stuff is near weightless and is easy to manipulate. I just compared it to a small sample they sent me of closed cell foam. The open cell really seems to be the way to go. It's much fluffier(?) than the closed cell.

I test fit some in a 450-400 Nitro Express and 375 H&H case. Since it's a rope, all I have to do is snip it to length and each piece will be exactly the same. There won't be any variation from cartridge to cartridge. It will definitely do the job of taking up the excess space and holding a charge of AA5744 in place against the primer. If I have need of it in smaller cases that won't be a problem as it cuts very nicely and doesn't fall apart.

Thanks for putting me onto this stuff. I was very nervous about loading a 115gr case with only 35gr of powder.