Recently shot about 30 different 357 reload recipes at the range and noticed the AA#9 usually left traces of unburned powder in the shell case and cylinder. On the range bench where I was shooting, there was also a pretty big pile of unburned powder dust on the bench. Many times while shooting I could feel a "dust storm" of powder spray my off hand.
All of these loads were with and without mag primers for a given bullet weight and charge amount. I also shot a number of different recipes with IMR4227 and W231 and these left no apparent unburned powder.
I now notice in an old AA reload handbook, it says AA#9 should be used with a heavy roll crimp, especially with heavy lead bullets. Will the heavy roll crimp help with the unburned powder? I use a Lee FCD and had these set on the light side of the crimp (1/2 turn in setting). I'm assuming the heavy crimp can allow the case to build more pressure and thereby burn the powder charge more completely. If this is the case, I'm wondering if AA #9 is a bad choice for plated bullets due to the sometimes difficulty of applying a heavy crimp. It will be a few weeks before I can make some new loads and test them.
With all three powders, I shot a variety of different charge amounts and primer combos with 125g FP plated Berry's, 125g XTP, 158g XTP, 125g Remington hollow points and 158g FP plated Berry's. As an aside, it seemed the best accuarcy was with max load of 4227 with 125g Remington hollow points. Firearm was 6" Dan Wesson.
All of these loads were with and without mag primers for a given bullet weight and charge amount. I also shot a number of different recipes with IMR4227 and W231 and these left no apparent unburned powder.
I now notice in an old AA reload handbook, it says AA#9 should be used with a heavy roll crimp, especially with heavy lead bullets. Will the heavy roll crimp help with the unburned powder? I use a Lee FCD and had these set on the light side of the crimp (1/2 turn in setting). I'm assuming the heavy crimp can allow the case to build more pressure and thereby burn the powder charge more completely. If this is the case, I'm wondering if AA #9 is a bad choice for plated bullets due to the sometimes difficulty of applying a heavy crimp. It will be a few weeks before I can make some new loads and test them.
With all three powders, I shot a variety of different charge amounts and primer combos with 125g FP plated Berry's, 125g XTP, 158g XTP, 125g Remington hollow points and 158g FP plated Berry's. As an aside, it seemed the best accuarcy was with max load of 4227 with 125g Remington hollow points. Firearm was 6" Dan Wesson.
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