I checked recently (started with this http://forums.accuratereloading.com/groupee/forums/a/tpc/f/1811043/m/856101974 ) several un-sized cast bullets and found that good number of them have the driving band in front of crimp groove smaller than groove dia for that specific calibre. Examples: 41 are .407-.0408, 357 are 355-356, 44 are .426-.428, etc. The rest of bullet has enough large dia-s so it could be sized to fit the cylinders. I remembered article in “Handgunner” about Keith bullets mentioning the same problem. It was done on purpose to make bullets fit all revolvers, regardless of cylinder bores. Author Brian Pierce (if I remembered his name correctly) pointed this as almost certain cause of inaccuracy, and, according to what I found so far, everything points that he is right on.
Now, the main issue with cast bullets is to fit hardness to the load so bullet will obturate properly; too hard, wouldn’t obturate/seal the bore under the pressure, too soft creates excessive leading. In that respect, straight wheel weight is just about right for velocities I am looking for; 1100-1200 fps so I can use plain base bullets, no gas check
If the proper obturation is desired and expected, how about mechanical obturation by some kind of die that will press the bullet and make all diameters uniform. The die should be designed to have adjustable stop so all bullets will be compressed on same height.
I found this locally available bullet for 40-65, see http://www.buffaloarms.com/browse.cfm/4,1547.htm , and looks as a good candidate to be bumped up to .411 dia, to be used in 41 Magnum revolver.
Anybody done this? Thanks, Onty.
Now, the main issue with cast bullets is to fit hardness to the load so bullet will obturate properly; too hard, wouldn’t obturate/seal the bore under the pressure, too soft creates excessive leading. In that respect, straight wheel weight is just about right for velocities I am looking for; 1100-1200 fps so I can use plain base bullets, no gas check
If the proper obturation is desired and expected, how about mechanical obturation by some kind of die that will press the bullet and make all diameters uniform. The die should be designed to have adjustable stop so all bullets will be compressed on same height.
I found this locally available bullet for 40-65, see http://www.buffaloarms.com/browse.cfm/4,1547.htm , and looks as a good candidate to be bumped up to .411 dia, to be used in 41 Magnum revolver.
Anybody done this? Thanks, Onty.