336 & C. S.,
Living here in the flatlands of Indiana, they have been very reluctant to have high powered rifles in the hands of most deer hunters. Up until a few years ago, all you could use was a shotgun and slugs or a muzzle loader or a handgun.
Then, several years ago, they made some pistol caliber rifles legal for deer. Most folks, and I was/am one that spent some time with the 500S&W Mag, 44Mag and the 45 Colt in various lever guns and single shot, mostly inexpensive Handi-Rifles, rifles. I just never had the desire for one of the other single shot firearms, those made by Thompson Center anyway.
The Contender just never impressed me and the subsequent versions didn't do much either. Then, I got to hearing about their 209x50 muzzle loader that was supposed to be a decent 200 yard gun with the right optics. I also found out that they were purchased by Smith & Wesson! (Had to put a plug in there!

) I didn't even buy my first 1911 until it could wear the S&W logo!
At any rate, back to the .358 WSSM: Ballistics are supposed to mimic the 358 Winchester. Case capacity is nearly the same, bullet size is. 225gr @ 2500fps "ish". With the 26" MGM barrel and the Encore, folks have been recording some phenomenal accuracy. One guy told me last night that he is getting 2" groups out to 400 yards! Now, THAT is impressive!
So, this round meets the criteria for our deer rifles here in Indiana. Next year though, they are supposed to lengthen the case specification to 1.8" maximum which will allow the 460 S&W Mag to be used. (That is the reason that MGM is making the barrels for them now!)
I suppose that the extra case length allowable next year will spawn a whole new breed of wildcat cartridges too. Oh, they are also making bolt guns with barrels on them too. Savage 10 & 110, Remington 700, Winchester 70 and others are being converted by the local store I got my barrel from.
I saw the mount of one that was taken at 350 yards with this round. Pretty impressive to say the least. DRT!