Currently I am using the 357453, a 151gr SWC. Yes, it does occasionally take a wiggle or two to get it lined up. I've also found that the factory magna grips seem to work the best for me rather than the larger "target" grips or the Pachmayr rubbermaids. Currently using 4.1gr Unique which for me is pretty comfortable. Going to a round nose profile should maike things just a little easier to get started straight. My first choice would be the 358311, a 160gr RN. Second choice would be the 358665, a 158gr almost RN.
With the 358156, are you using a gas check on it? A design that I have never tried as I've never particularly wanted to mess around seating gas checks.
There are very few wheelgun people in the group I shoot with, most everybody has gone to the bottom feeding multi-spitters. The truncated cone profile seems to be rather popular with the other wheelgun folk. They say it practically drops in without even having to look.
I am a bit more nostalgic though and would prefer going with a RN as my rig could be right out of the mid-60s. A S&W K-38 6" (1952 vintage), Bianchi Model 27 holster. Don't remember exactly when speedloaders came out but I carry 4 of them anyway. Also have a double dump pouch for another 12 rounds in Bianchi speedstrips.
If nothing else, it gets style points.