USSR
Member
...I didn't realize reloading was MUCH more art than science.
Truer words have never been spoken.
Don
...I didn't realize reloading was MUCH more art than science.
I didn't realize reloading was MUCH more art than science.
... there's not really much need for ALL cast bullets to have a Brinell hardness of 24 ... In fact, these hard bullets may well be inadvertently causing leading. How? These commercial alloys are commonly too hard to "bump up" (or obturate) and seal the bore at typical revolver pressures. The resulting blow-by of the hot gases past the bullet's bearing surfaces can leave significant lead deposits in the barrel.
There are very, very few revolver applications that require a BHN of over 20. In my experience, revolver leading can almost always be traced to some other factor (inadequate lubrication, improper sizing, barrel/frame constriction, etc.). Only very rarely is barrel leading caused by the bullet being too soft. In support of this claim, let me point out that many muzzle loaders prefer bullets cast from 30-to-1 alloy (which is quite soft, BHN of about 9) and these smokepole slugs are routinely driven to 1300-1400 fps. In addition, high-velocity .22 Long Rifle ammo uses an even softer bullet at over 1200 fps (and if a .22 leads, it's a gun problem, not an ammo problem). Elmer Keith's favorite cast bullet alloy was 16-to-1 lead/tin, which has a BHN of only 11. This is the alloy that gave a roaring birth to the .44 Magnum using plain-based cast bullets loaded to 1400+ fps. Properly loaded and lubed, Elmer's alloy will leave a magnum revolver barrel shiny and clean after a long day shooting.
Undersized cast bullets leave a gap between the bullet and barrel, leaving them unable to restrict this pressure-induced lube flow. As a result, the lube very quickly gets blown out of the barrel in front of bullet, leaving the bullet "naked", un-lubricated and unprotected. This phenomenon is especially problematic with the hard lubes; once molten, the low viscosity liquid lube gets blown out rapidly if the bullet is undersized.