First of all, it seems this thread has gone off into "Good-Gosh another Glock polygonal rifling and lead thread" (edited)... totally ignoring the S&W and Sig references...
S&W doesn't use polygonal rifling... so the issue isn't related to lead bullets (which sometimes smoke more due to the lube)
Next he mentions Berry's bullets (which are copper plated) and also a couple powder coated lead ones, which also don't smoke... so it ain't the bullets...
Finally he lists 3 powders and states that the same loads don't smoke in his Sig carbine... why do you think that is? Could it be because it has a longer barrel and the powder burns completely before exiting?
Now that we've narrowed the issue down to two pistol length barrels, what could the causes be?
o- Powders that are known to smoke in short barrels
o- Powder charges that are too low to burn efficiently in the short tube.
o- Insufficient pressure allowing incomplete combustion to escape around the case mouth, causing smoke and showing smokey ends on the cases.
I'm going with 2 & 3... Looking at the Alliant website guide, for the 115gr copper plated 9mm load, it lists 7.1gr of Power Pistol for the MAXIMUM load.
They also list 6.4gr as the max load for the 124gr GoldDot (another 'plated' bullet... plated are loaded similar to lead)
Power Pistol is known to create lots of gas and flash in short barrels. It is often loaded toward the upper end to get higher pressure and max velocity, so I suspect the smoke is due to the OP's loads are insufficient to burn completely.
Unfortunately Alliant doesn't list minimum or starting loads, so we will have to estimate it other ways. In addition many feel the Alliant data is inaccurate- some say it's weak, others say it's over max, so it's better to get a consensus from several sources and find a starting place somewhere in the middle. Using the the 124gr GD max of 6.4gr and using a 10% Off-the-cuff reduction, would put it in the 5.7gr range
Speer #13 lists a min-Max range for Power Pistol and the 124 GD as 5.6~6.4gr so I think we can yell BINGO! (<-exclamation). The max the OP lists is 5.3... (<-ellipse) well under the recommended Speer start and my -10% estimated minimum.
I think further googling will show the 115gr to also be weak as the 7.1 max will also have a higher min (about 6.4) since lead and copper plated bullets typically have higher charges overall than regular copper jacketed bullets.
BlueDot is another 'high pressure' powder meaning it doesn't perform well in light loads. It needs a certain pressure lever to burn efficiently, however it can spike pressure rather quickly... so working up slowly in the small 9mm case is a must - IMO it is more suited for magnum size cases.
Tightgroup is a relatively fast burning powder developing high pressures with small charges. It seems to have a small range between min-max so you have to be extra cautious with it. (many, many kabooms reported from people using this powder).
I've been loading since the 60's so my advice is to use several manuals, not just one -avoid data you get off the net, until you are confident with it... work up loads carefully 'in you guns' and pay attention to the composition and OAL for different bullets. Go over to the Castboolits website or some of the other well known reloader hangouts and read what others are saying.
and...
(use ellipsis... instead of exclamations!)
