My Smith M-57 was the first of my big bore Smiths. I bought it out of a GS in Connecticut along about 1978. At the time, I lusted after a M-29, but the Dirty Harry craze was in full swing and I couldn't find one. That M-57 showed up and the dealer called me to see if I was interested. I had the cash on hand and bought it straight away...it came with Smith's really long barrel, the 8-3/8" one and was superbly accurate. I've still got that first target shot at 25 yds with a strong handload...all 6 shots touching! That was back when I had the eyes for it.
Later, six months or so, I found that it had a small machining mark right at the muzzle and I took it up to Springfield to see if their repair shop could do any thing about it. They could and did, exchanging the long tube for the 6" one I really wanted...too bad too, that 6"er was never quite as accurate as the longer one, but was infinitely easier to tote around. I carried it back then in a skeletonized shoulder rig of my own design, using it to hunt and for woods loafing chores.
I've still got it, now with some snow in its hair, like it's owner, but as accurate and well timed as ever. Handloads do very well, and I doubt that I've ever shot a factory round through it. Powders? Try Unique or Herco all the way up to max, or Win 231 for milder work, and even SR4759 works well if pushed a little. I've done 296 as well, finding that it needed close to max to produce good results. For bullets, I've had excellent results with Remington's old 210 gr JHP, or Hornady's 210 gr XTP more recently, for the stouter loads, and Lyman's #410459 Gc cast from WW will do nicely for the milder stuff. Accuracy has always been great and load development a short, sweet process...groups run well below 2" at 25 yds with most any sensible load, with some of the special ones halving that size.
It's a heavy, but well turned gun...and the smiths at Smith did a fine action job when they replaced the barrel...probably the best of my revolvers, and that's saying sompin'. If you're looking for a good to great hand gun hunting caliber and the gun to support it...the S&W M-57 is a great choice....and no disrespect to Ruger's fine Blackhawk either, as I've a brace of them as well.
Best Regards, Rodfac (30 Cal's Dad)