A heavy sub-sonic .357 bullet

[Uberti]

I'm looking for a heavy cast bullet or bullet mold specs suitable for sub-sonic shooting / predator control.
 
For predator control at ranges point blank up to 50 meters, black bear and cougar.
To be loaded in a .357 max case.
Shot from a Uberti Baby Rolling block carbine rechambered to .357 Remington maximum.
I currently shoot Cast Core 180gr bullets seated in the crimp groove, and they *just* clear the blocks when loading, to give you the info that I don't have any wriggle-room with crimping location, but loaded in the max cases, there is plenty of room for powder. I shoot these 180gr. bullets at a conservative 1830 fps.
Prefer a meplat in the 70 percent range.
 
Barrel twist is 1-16. How heavy of a bullet will this twist stabilize? 220gr? 240gr? Heavier?
 
Thanks.
 
 
 
 
 

[Veral]

You stated that you want to shoot the bullets subsonic.  For low velocities I would reccomend that you keep the weight to not more than 200 gr, using our FN profile.  (It is the WFN pattern in 38 and smaller.)
  But you mention a conservative 1800 + fps.  For faster moving bullets the weight could easily be up to 240 gr, and if 220 gr or heavier the WLN would get the nod.  It has the same size meplat as the FN but a longer ogive, making it a bit more graceful.