Home Forums Reloading Big Game Rifles .358 Norma Magnum Brass

Hello new guy here. I've alway been a fan of medium and big bore rifles and the history that goes with them I've owned .35 Whelen's, .356 and .358 Winchesters, a .375 H&H, and currently a .450/400 NE Ruger No.1, .416 Rigby CZ 550, and a few .45-70's. Today I spotted an Interarms Mark X in .358 Norma Mag in a local shop and bought it. It has a 26" barrel and an old weaver 3x scope on leupold mounts. I don't know if this rifle was originally built as a .358 Norma or if it has been rebarreled but I don't particularly care. I've been forced to pass on three .358 Norma's in the past and I'm just glad I finally snagged one. I have a set of Hornady dies on the way and have a decent selection of .358 bullets around from past projects, I'm gonna pick up a pound ro two of H4350 tomorrow if I can find any. My question is considering that .358 Norma brass is a bit pricey and hard to find can I form this from .338 Winchester? I've read about people necking up .300 Win Mag while bumping the shoulder back, then trimming to length. But the thing is I have 100 pieces of Winchester .338 Win Mag brass I bought awhile back for a project I never finished. I realize overall the .338 brass is about .020" shorter and the shoulder is about .040" too far back but I suppose it might be possible. Has anybody done it? And what is involved?

Thanks, Kyle

P.S. Here's a few pics of the rilfe

Yes you can use 338 WinMag brass. It will be about .020" short if I remember right, then get shorter after you square the case mouths, but it worked OK in my rifle. Takes a long time to get to the correct length though. It's been a lot of years, but I just fired with a cheap light bullet (180 gr. pistol bullets I had laying around) with 50 gr. IMR3031 to get headspace on the shoulder right. The load is muzzle position sensitive. I used RP brass which held about 2 gr. less water than Norma brass after forming so showed 30fps or so higher velocity with all else the same. Thinking I saw some brass at either Midsouth or Graf's recently. Yes it is expensive, but lasts a while if not oversized.

There are still 4 or 5 boxes of Norma loaded ammo or once fired in the closet, but I have a few 300 WinMag cases ready to fireform to see how they work. Maybe this week. Lots of newer powders to try & I dont want to use up the good brass.

358WCF is right. Just run 338s through the sizer die.
I found fireforming unnecessary and used full powered loads from the start with no loss of accuracy.
H4350 is excellent for for 250, 280 and 310 grain bullets.
Big Game is also outstanding with 250s.
Varget and Reloder 15 work well with 225s

Thanks guys. This is exactly what I was looking for. I'll try a few without fireforming and see how it goes. If I find out I need to I'll anneal and fireform.

Well I loaded up 10 rounds for a test. A 200 grain hornady SST over 66.0 grains of H380. All 10 fireformed just fine, no cracked necks or any other negative signs. With the 3x weaver I only sighted it in at 50 yards. This thing is a beast from the bench, I think recoil may surpass that of the .375 H&H Ruger No1 I once owned. I wouldn’t call it unpleasant but you know it went off. I’m guessing I may have to re sight it after all my brass is formed due to a likely velocity loss. But only time will tell.

Kyle, low benches or high seats are not your friend when it's too hot to wear a heavy coat. My shoulder turned yellow with spots of purple last month because I'm stubborn, stupid, or dont feel recoil much. I got a pad in the mail to help with this last week. It works splendidly. I took 3 more than moderate recoil pieces to the range yesterday wearing a T-shirt & am unmarked today.

I shot the 300 WinMag cases yesterday. They were trimmed to trim to length for the 358 N.M. & ended up about .005" shorter after fireforming & resizing. There was a box of 250 gr. gas checked cast bullets & a can of SR 4759 in the closet. At 32 gr. the chronograph read about 1900 fps with virtually no recoil, but these are at normal pressure so the case filled out nicely. A rock at the 50 yd line took a few hits. Better than a 30-30.

H4895 with 225 Noslers shot real well at 100 yds. with good speeds out of some Norma brass with Fed. 215s. This was the 1st time I've shot 225s & am liking them a lot. More development after the monthly resupply gets here.

My local range has low benches. One of these days I think I'm going to make up my own seat that's lower than the ones they provide. I'm 6' 3" and the low bench doesn't help it also doesn't help that on Sunday I sighted in my Marlin 1895 Guide Gun with some 300gr Hornady hollow points at around 2250fps. I've decided that the rest of those are going to be saved for awhile and I'll go back to my 405gr cast bullets for most shooting.

I'm thinking in the long run I'll probably get a mold for the .358 so I can shoot moderate cast loads when I'm not up for a beating. As I mentioned in my first post I have a .450/400 NE Ruger No.1 and .416 Rigby CZ550 but I've never shot either from the bench. I also don't think I've ever shot over 5 or so rounds out of either in one day.

How hard is it to neck up .300 win mag brass to .358"? I had read about going that route the other day when I was just looking at the rifle online, the only issue was that I was having trouble finding anyone with .300 win mag brass in stock. Can you go straight from .308" to .358" or do you need an intermediate expander like .338"? I no longer have .338 dies I let those go with my A-Square Hannibal .338 a few years ago, but I had kept some brass. I do however have a .330" expander in my lee 8x56R dies. I've also read of people using 7mm Mag brass but .284" to .358" seems like a lot of expanding to me. It also seems like a lot of work if I had to run them through a .308" expander, followed by a .338" expander, and finally a .358" expander. I do know that if I ever come across anyone with .358 norma brass in stock again I'm going to grab 50 or 100 pieces even if it is a bit pricey.

Edit: I should have hauled my chronograph out but forgot all about it. Might just wait until I have fireformed brass to use.

I didn't know Hornady makes a 35cal 200gr SST bullet. As far as brass goes, I recommend you PM member, crod1972. He has some 338 NM once fired brass available from time to time and it doesn't sell as fast as other more popular cartridges do.

Thanks, Dinny

When I owned a 358 Norma, I necked up 338 Winchester Magnum cases to .366", then created a false shoulder for fireforming. I used the COW (Cream of Wheat) method. It saved my shoulder!

Oddly enough, I had a 3x Weaver scope on my rifle, which used a military Mauser 98 action. I hunted with it in 1991 in Colorado, but ended up shooting an elk with my other rifle, a 300 Weatherby.

I used to neck .280 Rem brass up to .35 Whelen in one pass with a tapered expander and RCBS case lube applied with a brush. It was a surprisingly smooth operation.
I would not expect any problems starting with .308.
But, again, I have made many .358 Norma cases from new Winchester .338 cases without any fancy footwork.
1) Resize .338 cases full-length a .358 Norma die.
2) Load with a normal, full-power load.
3) Happily fire away.
4) No lack of accuracy was observed but cases came out a bit short.
5) Trim to uniform length if you wish but I haven't found it necessary,
6) H4350 is your friend.

Cheers,
Walt

Yeah, I'm 6'3" too. My buddy, who's about 6'5" was kind of chuckling yesterday when I put the pad on. Asked if I needed some Mydol. I let him shoot the fouling shot with 250s leaning into the bench & he shut up immediately. RE: Your Marlin... Sloping butts with curved buttplates can be painful in a T-shirt. A long time ago my shooting/reloading/experimenting cohort had a Trapdoor & we were messing with black powder with heavy cast bullets. It was brutal with 500s at BP velocities. I think it just hangs over his fireplace these days.

Just looked & whoever had the Norma brass last month doesn't have it any more. I got 100 Prvi 300 WinMag brass for pretty cheap so it will be a good backup if the Norma stuff gets even harder to find. It looks like pretty decent brass. That, & it isn't too short after forming. Since you have the 338 brass already why not use it? Just be aware, with short cases, of the carbon ring forming at the spot where the chamber ends & the rifling starts. Worst case... If it gets well established & you do fire some full length brass there could be a pressure increase from the case mouth not being able to expand fully. Normal cleaning methods dont touch the carbon. I agree 7mm RM brass may take too much work if there's anything closer available. It will be too short as well.

The 300 WinMag brass is ready to shoot with one pass thru the 358 NM die set for my rifle to headspace on the shoulder bumped back approx. .002". You will be pushing the 300's shoulder back about 1/10 of an inch. The tapered expander rod from a 35 Whelen die screws right into the 358 Norma die (both dies Redding). I use a good coating of Imperial (I think Redding makes this nowadays) sizing die wax on the body with their dry neck lube & haven't lost a case yet. Deburr, trim to length & load. I'm unsure if there will be a donut problem but will keep an eye out for it. The standard Norma chamber has a long freebore so bullets may never get seated to the base of the neck in my rifle. Hopefully your die maker has a 30 to 35 tapered expander ball available seperately for a few $$. I know Redding & CH do.

Thanks this method is what I've been doing so far. Unfortunately nobody around here had any H4350 so I ended up going with H380 as H4350, H380, and H414 are the only powders that Hodgdon lists. None of my load manuals have data for the .358 Norma Mag. The ony data I've found is from Nosler and Hodgdon, might have seen something from Barnes but maybe I'm remembering something that didn't happen. So far so good though, I'm hoping to shoot a few across the chronograph tomorrow. I know that at this point I feel like for $500 I got one heck of a deal on a whole lot of rifle.

Thanks for the info. My Marlin has a factory recoil pad that's fairly thick but even so those hot 300gr loads hit hard on both ends. My 405 cast loads at trapdoor velocities are quite pleasant to shoot. I will keep an eye out for the carbon ring, I've had a similar issue from firing .38 specials in a .357. If I remember correctly the .358 norma trim length is 2.520" my .338 brass came out of the box at 2.480"-2.485" so I currently have the trimmer set for 2.480" for initial brass prep.

I was mistaken the bullets I have are the 200 grain FTX that they make for the lever guns. I was using them in my .35 Remington a few years ago. Probably not the best bullet for the Norma but I had less than 50 left and figured I'd use them up. I also have about 250 Speer Hot-Cor .358's both 200 and 250 grain. As well as some Barnes 200 and 225 gr, both the polymer tip and hollow point. And I believe there is a box of Nosler's somewhere.

Data is scarce in the manuals. Ramshot Big Game and IMR 4451 work about a good as H4350. I worked up to 2800 fps with 250s (24" bbl) and found that 4451 needs about 1 grain less and BG uses 5 gn less to reach that velocity.

Yeah data is scarce. New data with new powders is even scarcer. FYI... It's a few years old, but there are a few useful Quickloads in this thread.

https://forum.nosler.com/viewtopic.php?f=4&t=33599&hilit=358+norma

I have found IMR 4320 to be prairie dog accurate. You give up a small amount on vel and recoil is mild.
Too bad you didn't check the classifieds, I have an extra set of RCBS dies for sale.

Thanks guys. I’m pretty happy so far with the H380 load I tried. I took it out Tuesday and put another 10 rounds through it. Next time I’ll take the chronograph. I took it along last time, then upon getting to the range I realized the battery was dead. Hodgdon says it should do right under 3000 FPS in a 24” barrel. The barrel on my rifle measures 26.75” from the bolt face to the muzzle.

I wouldn't trim the brass at all. Fire form first you will in all likely hood still be short of 2.519" might not have to trim for 2-3 firings. I make 308 Norma Mag out of 338 ww mag so been there. Next don't count on 3000 fps Nosler #8 only shows about 2700 fps the 358 STA only crowds 2900 fps. MB

I like My big Swedish lady a awful lot!!

Mine likes a diet of IMR4350 and 250 Norma Oryx bullets at almost 2800 fos. Yea it thumps but #1 Im not shooting a box of ammo every time and 2, I changed the stock to a Bell & Carlson (alot less drop) then fit a KICKEEZE pad! Far far better!! Mine is a rechambered 7mag Winchester Pushfeed. JES did a awesome job as always!

I have a Accurate 36-270c mold and loading that on top of a NON COMPRESSED full load of trail boss gets me 1700 fps and 1" @ 50 yard accuracy!! I wanna use it on the wxtra doe season!!

CW