ben hunchak said:
Does anyone have an opinion as to why this chambering isn't more popular.....It would seem to cover most big game/long range applications!
Well, it is a .358 for starters, and for whatever reasons you care to suggest, .35's have never really caught on.
Second, except for those who bow at the feet of the God of Velocity, it won't really do anything a .338 Win Mag won't do - and without diving into reloading manuals, a .340 Wby Mag will probably match it. Factory ammo is available for them, and the chamberings have a relatively familiar ring to them in many hunters' ears.
Having said that, I've owned and loved .358 Norma Magnums and am contemplating having Bill Leeper build me a .35 Newton now that brass is being made again. And I have a brother that Bill built a .358 STA for; he has used it to knock over assorted elk, moose, and a grumbly bear I believe and it is a tack driver. So... there is nothing WRONG with the .358 STA and its' close kin. But pragmatically speaking (and ignoring those of us who read ballistics tables like kids read comic books), the .358 Loudenboomers of various persuasions are no better and no worse than their much more available and easier to feed .338 factory cousins.
Also too, in the .358's, once you get past somewhere around the .35 Whelen/.358 Norma Magnum level, every velocity gain past that point requires a lot more powder. And overbore guns of any caliber ultimately deliver a lot more recoil for whatever gains they also deliver in velocity. If the extra velocity is important to you and you don't mind the extra recoil and powder burned with each shot, then Bob's your uncle and it will be a marriage made in heaven.
But the big .35's are a hell of a lot more versatile and easier to shoot on the cheap... although that's a different discussion.