Old Ironsights
09-27-2006, 09:44 AM
Ok all you (low) tech weenies...
At what point does 3F become 4F where it becomes too dangerous to shoot as a main charge?
3FG = .84mm —.29mm / .0330in - .0114in
4FG = .42mm —.15mm / .0165in - .0059in
Note that there is a fairly large overlap in grain size from the middle of the 3F range to the middle of the 4F range.
Remember when I sifted a variety of powders? I was using a 30-mesh screen (.0233 hold) which lead to things like 20% to 80% "failure" - i.e. up to 80% of the granulation went into the "4F" pile.
Admittedly, that meant that all grains from nominal .0232 to .0166, which "should" be considered 3F got sifted out, but still...
Now a 40 mesh screen will hold down to .0120 - .0150 depending on (practical) wire size.
Given that 4F can be as large as .0165, would you consider .0120 "3F" (still in the 3F granulation range) safe as a main charge? (This is assuming a large volume case OLD gun or a muzzle-stuffer.) :confused:
At what point does 3F become 4F where it becomes too dangerous to shoot as a main charge?
3FG = .84mm —.29mm / .0330in - .0114in
4FG = .42mm —.15mm / .0165in - .0059in
Note that there is a fairly large overlap in grain size from the middle of the 3F range to the middle of the 4F range.
Remember when I sifted a variety of powders? I was using a 30-mesh screen (.0233 hold) which lead to things like 20% to 80% "failure" - i.e. up to 80% of the granulation went into the "4F" pile.
Admittedly, that meant that all grains from nominal .0232 to .0166, which "should" be considered 3F got sifted out, but still...
Now a 40 mesh screen will hold down to .0120 - .0150 depending on (practical) wire size.
Given that 4F can be as large as .0165, would you consider .0120 "3F" (still in the 3F granulation range) safe as a main charge? (This is assuming a large volume case OLD gun or a muzzle-stuffer.) :confused: