Home Forums Hunting & Shooting Custom Rifles & Wildcats New Mid - Bore!

Today I did some researching once again and decided that I wish to turn one of my model 70's into a .358-STA caliber.

This caliber will shoot the 275 grn bullet at 2850 fps and deliver more energy than the .375-H&H at the muzzle, plus shoot flatter than a 30-06 caliber.

This caliber has a "shocking Index" of 500 compared to 325 of the .338 Win mag shooting a 300 grn bullet, at 2500-fps. Also the penetration factor gives the .358-STA a penetration rating of 151 verses the .338-Win mag of 131.

Check the recoil index #'s

If the those #'s are tolerable than you are going to have one heck of a hammer!

The 358STA is one of the several too oft overlooked excellent catridges. I shoot a similar 340 Tyrannosaur. Same case but necked to 338. I am running 225gr TTSX's at 3100fps. A fast and flat hammer as well. I am with ya, love the STA series but I built and named my wildcat the Tyrannosaur before the STA series was known much or gaining traction.

Did you look at the 358STA with 250gr TTSX'S? Should be able to get to or near 3000fps. Can't see what one would poiint a rifle at short of an Elephant that would not fall to such. In a model 70 no less! Great choice, I can already tell I am going to like the build.

I am seriously considering a 340 Roy barrel after I get my 300 rolling again.

Mark, what cases are you using? I am somewhat concerned about 8MM Rem. Mag case quality...

I use remington 8mm Mag cases necked up with a set of 340WBY dies. The cases I have are fine and I have used a lot of Remmy brass over the years with no difficulties. As always, YMMV.

I am under no delusion that my wildcat is vastly superior to a Roy, It's just a little bit different, a touch faster and its MINE, if ya know what I mean. Oh, and brass is much cheaaper, or at least it WAS when I started this project. Seems to be going up some but I have a boatload of it loaded up and stored up.

Tonk I had one before it was the 358STA...it gives over 3000 fps with a 250,and 3150 or so with the 225.Never used heavier bullets than that....barrel was a 24" 12 twist Krieger.

It took 92 gr RL19 to get that velocity with the 250 gr.I formed cases by necking up 8mmRem Mags, or blowing out and necking down 375 H&H cases.

At the same time I learned that a 24" barreled 375 H&H weighing 8 pounds, used 78 gr 4064(today I use RL15)to get 2940 with a 250 Bitterroot.

With both zeroed 3" high at 100 yards, the 358 wildcat dropped 9-10" at 400 yards; the 375H&H combo dropped 13-14"....I decided the 35 was not worth the bother for 4-5" less drop,a lot more powder in the 35,and a lot more recoil.The 375 is far more manageable.

For anything on this continent,there is not enough difference between them to bother with....I hate to be a wet blanket but there is nothing the cartridge does that a properly loaded 375H&H or Ruger will not accomplish as easily and with a lot less fuss..

But then....there IS the Rifle Loony factor to consider....so if you like it, go for it!

Which can be said when comparing any number of cartridges.

Take for example...say when comparing a 7mag to a Mashburn......

aalf: Like I said in the post....no accounting for looneyism!

If he wants it he should go for it,which I also said

BobinNH nah, your not raining on my parade one iota! I got the information from Art Alphin sometime ago and put it into a journal of sorts. Spring cleaning on my bench (it needed it badly) and I found it once again. I told him next time he gets back, we are all going on a hunt in Africa, so now he will have the rifles to get the job done, both are model 70 Winchesters.

Then I compared with Arts reloading manual and sure enough those fellows got a 2850 with a 275 grn bullet. My youngest son is going back over to his outfit in the Afgan mountains, so I gave him my Safari grade model 70 in .338 Win mag. It has been to Africa a acouple of times.

So I got this idea for a new rifle, it will help keep my mind off things, I don't need to be thinking about down the road.
I figure if "Safariman" likes it, it must be a winner on big game animals. I sure do like the write ups and those figures impress me. BobinNH, I already have a .375-H&H, plus another .375-H&H that was rechambered to .375-Wby. I am also giving the son the .375-H&H model 70 also but he does not know that as of yet. He got another stripe (E-6 Sgt.)on his arm and I figured it would make a great sending off present.

Well Tonk looks like you have everything surrounding the 358 STA;so put it together and have at it.I was in no way trying to discourage you;simply explain my reasons for not continuing on after using the cartridge. I like to keep things simple in the over 30 cal category

I had Jack Atcheson,Jr at the range with me one time shooting the rifle,years back. He loved the thing!

It's a great cartridge just a lot of recoil....it'll do those velocities with a 275 gr I think. I recall it was an accurate rifle.Those 35's and 375's do shoot!

BobinNH, I realize that you were just trying to state the facts or reason for you not going that route. I am actually very content lately with shooting my newer 6.5/06 but I wanted something new to take to Africa and keep my .470-Capstick company. Something that would reach out also across those plains as well. I also am axious to see how it does on the shoulder of an Eland using that 275 grain Swift A Frame bullet. I once had a TBBC bullet in my .338 Win mag not penetrate a bull elands shoulder.....Wow! that was some thick bone. I needed the new project anyway folks!

I want to do a 300-358 plus factor is 300Win brass is easy to find and cheap.

Tonk--
Do you have the H&H magnum length action, or will you be starting with the standard length action?

I already have a model 70 Winchester rifle (new) the long action never bothered me one bit. The more I look at this caliber, the better it looks to me.

This taking in the 275 grn bullet (might be a 300 also) the velocity of 2850-fps according to "Any Shot You Want" manual. The kinetic energy of 4960-lbs and the Shock Power Index of 500.