Filler?

[kevinsmith5]

I'm loading 150 gr collar buttons for 45-70 and really think a max load would be a little overkill.  Since the seating depth is pretty short I have figured out that a full case in this load would be the full 70 grains.  I have looked at various sites for what other people use as filler sin the case for a reduced load and seen everything from grits, to cornmeal, to dacron batting, to even cream of wheat.  I thought I'd check here to see what thoughts anyone here had.  I figure at most I want 50 grains in the load, probably less.

[John Traveler]

The American Rifleman Technical Advisor has taken a position AGAINST using dacron fluff fiber filler in large volume straight cases.

For a couple generations, cast bullet shooters got into the habit of using polyester ("Dacron") fluff fibers as a filler for reduced loads in large capacity cases.

It's been studied quite thoroughly by the Cast Bullet Association, and determined that use of fluff fibers in straight wall rifle cases (.38-55, .45-70, .45-90, .45-110, etc) can result in chamber/bore obstructions and cause "ringing" chamber damage.  It is believed that the fluff fibers melt and stick to the bullet bases, building up to the point that chamber pressures thrust not only the bullet forward, but melted obstruction outward, bulging the chambers.  This has happened often enough that it presents a real hazard to even the experienced reloader/shooter.

"Natural" fillers such as cotton fibers, toilet tissue, and card wads seem to present no such hazard, and are used extensively by the BPCR shooters.

[kevinsmith5]

Cotton? Hadn't heard that.  What about the cornmeal?  Several people on Cast Bullets recommend coarse wellow cornmeal.

[John Traveler]

Cornmeal, Cream of Wheat cereal, etc have been used and recommended as filler material.  Cotton fluff from cotton balls and first aid kits has been used too.  It was written up by a BPCR shooter in Rifle Magazine, or maybe it was Single Shot Rifle magazine a few years ago.  The reason for emphasis on natural materials is that it will either combust completely, or be blown out of the barrel during firing, unlike polyester fiber which tends to melt and clump.

[longcaribiner]

British manufacturers in the 1800's sometimes used carded wool.      I have used wads and extra thick grease wads in the past.