onondaga
posted this
21 September 2015
http://castbulletassoc.org/view_user.php?id=608>mtngun
Consider a different scenario to identify the cause of the uneven engraving and tipping of your bullet on firing.
I believe your BHN40 bullet metal is so far out of line with the load pressure that you are working with, that the tipping and uneven engraving are only a couple of the results to be expected with such a severe mismatch of load level to bullet alloy. I believe the severe mismatch is the cause of the defects you are seeing. Your load does not require harder than BHN 15-17 bullet alloy and a harder alloy changes predictable results to unexpected results as bullet fit is critical in different ways with the alloy being correct or incorrect for the load level and your mismatch is severe at BHN 40.
Both of the chamber throat types shown in your chamber castings are workable. A bullet diameter with a sliding fit upon chambering and a bullet alloy matched to the load level will work fine for either type of chamber. The bullet alloy mismatch you have is so severe it will exacerbate the smallest discrepancies in bullet fit and load pressure badly, even to the type of distorted bullets you picture.
You are actually ignoring the basics of cast bullet shooting by so much that your drastic results are not surprising at all. Your results actually demonstrate that Richard Lee is correct in his chapters on load level related to bullet alloy in his book Modern Reloading 2nd Edition.
Want to fix this? Size BHN 15-17 bullets so that a bare bullet is the size that slides with a tactile touch into the throat and seat the bullets to the LOA that engages the leade taper .010” past initial contact. That is following the basics and much different than what you have done. You actually cannot take full advantage of a good bullet fit when you use the wrong alloy. A poor bullet fit and a poor alloy selection accentuate problems and difficulties as your results demonstrate.
I have no idea how you became convinced that BHN 40 bullets are suitable in your application. They are not and they are not suitable by a wide margin. Certified Hardball Pistol alloy or Certified Lyman #2 alloy fits your application with throat fitting bullets seated to engage the leade .010” regardless of action type or barrel maker.
If you just want BHN 40 bullets work, that can be done but your load pressure is too low and your bullet fit is insufficient.
Additionally a #2 alloy flat nosed bullet with a matched load and fit for your firearm will expand on impact with game to 70 caliber and pass through at reasonable hunting distances, a BHN 40 bullet will only pierce a .357"hole and deliver little shock. The simple Lee TL 358-158-SWC, C 358-158-SWC or 358-158-SWC in #2 alloy would be a much better choice for 100 yard deer or pig hunting. The gas checked C 358-158-SWC will handle the highest load level for hunting if you need that.
Gary
