Fire forming H&H case

[cowboybart]

I'm fireforming 40 or so pcs of standard H&H brass to 375 AI. I'm going to be using 260gr cast and Unique. I don't eat Cream of Wheat or oatmeal, so I don't have any in the house. What other filler can I use and how many grains of Unique in that sized case?

 

[Rich Coyle]

I would and have used fiber fill for making pillows for filler. I used 15 grains of unique.

 

[MagnumManiac]

Rule of thumb when using pistol/shotgun powder is to use 1/3 of a full power load. When I was forming 375 Weatherby from H&H cases, I used 30gr of Universal to get fully formed cases and COW as a filler. I don't eat it either, a bag was cheap so I just bought one and used it.
I had to work up, as nearing the full case expansion I discovered that the barrel was getting dirty causing pressure issues.

Cheers.