Home Forums Hunting & Shooting Custom Rifles & Wildcats 358 STA

Finally getting the STA project off the ground and have a couple questions to those who have one...

When using 8 mag brass necked up, are you using a fireforming load the first firing or just load your regular loads and shoot?

Any pet loads for the 225 TSX? Thinking H4350 since I have plenty...with H4831 as second choice.

Assuming you have gotten past the necking up part, I am pretty sure you could try full power loads.....but it doesn't hurt to start a couple grains lower for first firing.

It has been a few years since I had one, and mine was made before there was a 358STA,but mine was a straight 8 mag necked up with no other changes....I think the STA is very slightly blown out vs my version of the cartridge; but not much. I would start low and then work up to max for formed cases and see how it goes.

I did not have special dies made for mine and when the rifle showed up I had a 358 Norma neck and seating die; to neck up I used a COW load with 2400 to form the necks with large pistol primer(I did not want to force the necks over the 358 expander ball). This worked great and I would then size the necks with the 358 Norma neck die; worked so well I never did buy special dies for it.

So my first firing loads were full power. Eventually I got tired of chasing 8mm Rem Mag brass and started forming cases from WW 375H&H by first necking them to 358,then blowing them out with the COW load. I liked this even better.

I am working from memory here but I believe I was burning 92-93 gr of RL19 with the 225 gr Sierra for about 3150 fps...90-91 gr with the 250 for a bit over 3000 fps. My barrel was a four land Krieger....if you are working with a tight button barrel, these charges may be a shade on the heavy side....start low and work up.

While I have an STA I can't really help you much. Bought Superior Ammo STA brass after Qual-Cart brass was used up, no fire forming.

When I started down this path 10 yrs ago I worked up a load for 225 NP. Swap bullets to Sierra GK's for paper (prints within an inch of NP). Load is 92gr RL22 Fed 215 primers.

That said I started working loads for 200gr TTSX but no range time until medical issues clear up a little. Figure 3-4 wks.

They need fireforming, as you're improving the case. How you go about it is your call.


I worked mainly with the 250 Partition, as my goal was to use it on BB. I've since sold it and don't have my notes to help you. There's plenty of info out there, so you're not totally in the dark. Mine was set up as a switch barrel, with tubes in 7STW, 358STA, and a third in 375H&H Improved.

I had a .358 STA built in 1999 on a Win 70 Classic which originally was chambered in 7mm STW. It was re-barreled to a .358 STA using a 24" Douglas barrel. I started with 375 H&H Win brass necked down and a charge of 80.0 grains of H 4350, 250 grain Partitions and CCI 250 primers for fire-forming. Later I tried 225 grain Ballistic Tips with Ramshot Hunter powder. I ended up topping out at 87.0 grains of H 4350 with 250 grain Partitions even though Layne Simpsons' article in Shooting Times in November 1997 went as high as 89.0 grains of H 4350 with this bullet. That same article suggested fire-forming with 80.0 grains and working up. Barnes #2 went up to 84.0 grains of H 4350 with their 250 grain bullets.
With the 8mm brass necked up and CCI primers, I only tried the 225 grain Ballistic Tips and Hunter powder. I started at 83.0 grains and went up in one grain increments until I had extraction difficulties at 89.0 grains. I spent about two hours at the Miles City offices of Ramshot powder with Johan before I tried these loads. I never went back to 225 grain bullets since Nosler discontinued them shortly afterwards. I am with BobinNH in that I much prefer starting with necked down 375 H&H brass over the 8mm brass. In fact I have 50 virgin Rem 8mm brass and 16 once fired that I would sell if you are interested. H 4831 also was good with the 250 grain Partitions. Nosler # 4 was the manual I started with.

358STA 225gr TSX load is 91gr of RL19 @3100fps.....

Impressive round. I never could justify one,but I've always been intrigued by the thing. What a hammer.

I thought so, too...and it is. But then I discovered that a 375H&H would push a 250 gr Bitterroot at over 2900 fps with 77-78 gr 4064 or RL15,(a lot less powder than the 358)kicked a lot less and dropped only 4-5 inches more at 400 yards than the 358.

There was not room for both and I sold the 358.

Yeah, that's why I only had a .358 STA for a couple of years. Found out it was basically a variation of the .375 H&H, but wasn't legal in Africa for dangerous game, and there wasn't much ammo in sporting goods stores! But it was fun to fool around with.

JB it IS a fun cartridge.....but it was more fun than I could handle. I still have the dead brain cells to prove it.

I was a cow man most of my life, but have no experience with cow case forming.

From what I gather, enough cream of wheat over enough fast burning powder will open the shoulder and the neck with one shot?

What does burned cream of wheat look like all over your shop ceiling and what magic potion does one use to get that stuff out of a perfectly good rifle barrel...?

BTW, I sold all my cows, no cows are better, especially in the cold, rainy winter...

DF

What cartridge were we talking about?

I didn't find it kicked any worse than my .375 H&H, probably because it weighed about the same, around nine pounds scoped. But I was younger then! Didn't mind my relatively light .338 Winchester a decade ago, even with 250's at 2700. It weighs a little over 7-1/2 with scope, but for some reason I haven't hunted with it recently, even with 200's at 2900+....

JB mine started the 250 gr a over 3000 fps, or a bit faster than in the 375H&H.Both rifles weighed about the same, about 8#'s scoped.But it was the difference in powder charges that did it. In the 358 I was burning about 91-92 gr of RL19 to get that velocity and in the standard H&H round,77-78 gr of the faster powder.

The H&H round was easier to shoot, and recoil was slower, softer somehow....the 358 seemed to be a neck snapper, faster and harder like a 340 Weatherby. Long sessions got tedious.

I still have that 375H&H and it is not an unpleasant rifle to shoot.

DF, yes with the charges of 2400 ( I forget the precise amount; Bill Steigers helped me here because there is a formula you use to determine how much powder),large pistol primer, and fill the case with COW to base of neck. This is topped off with a small wad of tissue paper to hold everything in place.

When fired in the rifle (at the range and into the air; not in your basement ) the neck would be perfectly formed to the chamber, and in the case of the 375H&H brass necked down, a slight increase in powder charge gave perfectly formed STA cases ready to hunt(you do have to run the case through the FL die to bring the neck back down to dimension).

There is no COW left; it all burns or is ejected out the barrel. A few strokes with a dry brush knocks the residue loose; I do this every few rounds, followed by a cleaning with solvent at the end of the forming session.

Why do it this way? Because Steigers recommended it...he made many wildcats, and felt pretty strongly that perfect function is the most important thing in a rifle for BG hunting, and that new brass should be used to hunt with a wildcat since it still retains the ability to bounce back after firing with a high pressure load; and brass loses some of this resilience with each firing.

I have only had two wildcats so what do I know; but I only hunt with new brass in any of my rifles anyway.

I always thought the 350 G&H Magnum was a cool old round.