Thank you,Bullet is a 250 Keith style SWC cast by me, soft, not hard. 8.5 Unique comes in about 900 fps in most of my Colt or Ruger revolvers. 9.0 Unique hits about 1000 fps. Good loads in all my revolvers.
and right hardness. I can't say higher pressure loads are 'more' accurate. All I have to do is look to the .44 Special and know that isn't true. Almost every load I tested (lots of powders) with a 240gr SWC (BHN 15) was marked as accurate. Same with .45 Colt. These are low pressure cartridges. It really comes down to the gun. For example one of .45 Colt SAs struggled to get 6" groups at 25 Yards. I reamed the cylinder throats to .452, changed forcing cone to 11 degrees and the group size shrunk by half to around 3". Then firelapped it and that made the group a tad tighter (as good as I can shoot a fixed sighted revolver). Made the gun 'acceptable' to shoot! If the dimensions are right in the gun and the bullets are sized right and of correct hardness for the pressure, the odds are the gun will really shoot well.get the right sized cast bullet.
Yes, true but.... should state that bullet sized to match the cylinder throats with the throats .001 over the bore size. That is what helps 'seal' the bullet in the bore. Since in .45 Colt (Ruger anyway) the bores are .451, the throats should be .452 with the bullets sized to simply pass the throats with finger pressure. If the throats are oversize, the bullets should be sized accordingly (that is why some .45s require .454 sized bullets for example). If the cylinder throats are less than .452, then the throats need reamed. And of course if the bullet is of the right hardness, it will also bump up the size of the bullet (Obturation I think it is called) to help seal the throats and get pass minor imperfections in the bore as well. Everything works together to make a good shooter . The purpose of the seal is to keep the hot gases behind the bullet... Otherwise the hot gases will get by the bullet and cause leading which will affect accuracy.Ideally, the bullet should be properly sized to match the gun for optimal sealing,
Correction 'throats' . The chamber is behind each cylinders throat. And yes, the throats may be different from gun to gun. That is why all of mine have been reamed uniformly to .4525 and that ... is that.Not all chambers...