I just got a 2005 Bisley stainless 5 1/2" Convertible. It shoots ok but I feel it can do better. I measured the throats on the cylinder (only came with the 45 ACP...thank god 'cause Ruger won't sell you and ACP cylinder!) and they are .449" for 3 and .448" for the other 3 throats. I measured my friends Bisley from 2000 and his were dead on at .452". And his shoots great! I have read about them being oversized....but not about them being too tight. My cylinder is getting throated to .452" as this is written...can't wait for it to get back! I have over a dozen different loads to test! I wonder if it is only in the 45 cals or are the other Blackhawks having these over/under sized throats? What do you have and what does it measure?