A number of years back, Brian Pearce wrote an excellent article on .357 magnum carbines in either Handloader or Rifle magazine. Based on his testing, IIRC he felt that when fired from a carbine, it compared favorably with the 30-30 when using bullets in the 150 to 170 grain range. His fastest loads were right at 2,000 fps. People who have not taken game with the 357 (or the 41 or 44 magnums) have no idea of how much critter they will penetrate, even with velocities down around 1,000 fps. With todays monolithic bullets (Barnes, etc) your .243 will now likely equal the penetration of a 357 on a stem to stern deer shot. Until those bullets came along, the 357 with a decent bullet design and weight would often out penetrate most 6mms. Artificially limiting the 357 to 100 yards on deer from an accurate carbine is silly, and such arguments are nearly always based on "common sense" or the old "'cause everybody says so". Look around on the internet for other opinions. Look at Tim Sundles Buffalo Bore ammunition web site or Double Tap ammo's web site for modern 357 loadings. Google "hunting deer with 357 carbine" and see what you turn up. BTW, they're both fun guns, in useful chamberings.
Dave
"A strongly held opinion is not necessarily the same as a well informed opinion."