Tony60 (Login tonyk60) Posted Jan 26, 2014 12:31 AM
I went down a different path. I went to my local tool shop and had another expander die made up for my Dillon 550 that was .357 diameter and also the same length as a 148HBWC. I have found over the years that even just by loading the swaged projectiles into a normally sized and belled case it will cause some compression of the diameter of the projectile. Most sizing dies will resize the case to minimum dimensions according to SAAMI specifications, by putting a swaged HBWC in these cases (and all have different wall thicknesses) you will in fact reduce the diameter of the projectile. We are after all talking about a relatively soft projectile. just pull one and mike it up to show to yourself. Although the skirt will flare out to fill the bullet lead in the chamber and forcing cone etc, the head of the projectile won't, therefore causing leading and inaccuracy.
By having the head of the projectile supported through the firing process I have reduced my group size over a Ransom rest to sub 1 inch groups at 50 yards. I also don't have to put as much flare/bell on the case as the internal dimension of the expanded case is approximately the same as the projectile. always take into account that the brass in itself has some maleability and will spring back slightly after belling.