How to make 358 Norma from 300 Winchester cases

358 Norma Brass is expensive, hard to find and a bit soft. I make my 358 Norma from 300 Win Mag and get better case life and save a bundle of money. Here is how.

[@outspokengenius]

Just a tip I learned from the guy who sold me my .358 Norma. He used and I am using .338 Win Mag brass, a lot less work than .300 Win Mag. Just run them through a .358 Norma sizing die to open up the neck, trim to uniform length, load, and fire. The shoulder will fireform and blow forward the approximately .040" it needs to go. The brass will be a bit short my Remington .338 Win Mag brass came out of the bag at about 2.485"-2.490" when it really should be 2.500" and .358 Norma would be 2.520". I just trimmed it all to 2.480" and let it go, I was told to watch for a carbon ring in the chamber but so far so good. I've only put 30 or so rounds through it as I have several other rifles I'm currently working with. Note: When I bought my rifle there was no .358 Norma brass in stock anywhere, guys on forums wanted $1-$2 a case for their brass, and .300 Win Mag brass was also out of stock everywhere but .338 Win Mag brass was plentiful and the same price as .300 Win Mag brass.

[@north61]

I was worried about the excess head-space and the shoulder blowing forward but maybe I'll give it a whirl.

[@roadkillanonymous4807]

Use what you can find for sure haha. I’ve hD no issue with my .300 brass BUT I owned a .300 Winnie for years before I got my .358 so I had a veritable stockpile of brass available haha

[@johnnydawson7675]

I have made .358 Norma from .300 Win Mag and I just leave it long in the neck, the standard .300 Win Mag length.

[@north61]

I guess with a rifle with lots of free-bore that might work.

[@roadkillanonymous4807]

I haven’t even bothered with annealing or multiple sizing steps! Just ran once fired .300 win through the .358 sizing die and no problems. Did have 3 split necks out of like 40 cases. We’ll see how it goes

[@craigleibbrand7761]

Excellent video. The Reamer got away from the gunsmith so my chamber accepts full length 300 Win Mag necked up to 358. I wanted it throated for the 310 Woodleigh bullet. I'm not sure where the free bore stops but it is accurate with 225, 250, 275 and 280 bullets so I guess not all is lost.

[@roadkillanonymous4807]

Sounds like a more practical chambering anyway haha

[@Spruce-Bug]

Would it be beneficial at all to anneal between sizing through your different dies? What a clever solution. Well done. i'm impressed.

[@terrywagner7551]

I have been watching your videos for the past few weeks, this is just a suggestion you need a stronger loading bench. I have been reloading for 55 years and it’s interesting to watch you make a case for one that isn’t available anymore, such as.307, .356, 6mm Tcu, 30-30 AI and many others. I always liked the.358 Norma 👍

[@north61]

Yup..I upgraded recently. Much easier

[@ThemantleofElijah]

North, I am embarking on building either a 358 Norma mag or a 375 ruger. I am wanting to know what u would do? The weapon is an FN mauser chambered in 7rem mag now and gonna have it rebored and I have the choice between the two. Using it to hunt everything from deer to elk and whatever walks I guess. I’m a handloader too. Thanks

[@north61]

Both great cartridges. Given supply problems I might go 358 Norma as you can make the case from almost any medium to long magnum case and I have a ton of 358 bullets. 375 bullets might be just a bit easier to find . Factory ammo also might be a bit easier with the 375. It's really a wash. If you go Norma try and find a 12" twist barrel so you can shoot good heavy bullets. The 14 and 16 are a bit too slow.

[@ThemantleofElijah]

@@north61 perfect, glad to have the guidance. I was leaning more toward the 358 Norma anyhow. I’m having it done as a reboring job by a guy who specializes in such work with all different calibers in the 338-375 caliber.

[@TheWolfgangfritz]

Excellent! I've got a Winchester 356 model 94. Bought it in 1986 and haven't been able to find ammo for it for decades! Please put together something that has you use 444 Marlin Brass ( or is it 308, I forgot), and reforming it into a 356 Cartridge! Sure would appreciate someone doing that for me!

[@stienfamilyoutdoors]

I found a lot of resistance sizing from .300 to .338 - I’m guessing you find the 8mm step helps to make that a bit easier?

[@north61]

Yes..makes it easier and maybe less stress on the brass.

[@tylermettler3906]

I assume you can use 338 Winchester also?? would it make it a little easier? I'm thinking about getting one.

[@north61]

Yes... the shoulder needs to blow forward the first fire forming which worries me a bit but many people do this without issue,

[@jpr9954]

I've read suggestions about forming this brass from a 7mm Rem Mag case. Have you tried that or have suggestions?

[@north61]

Better to use 338...both would need to blow the shoulder forward a bit... the 7mm to 35 is working the brass quite a lot more than I like to.

[@jimv.661]

Beware of Norma Brass! Safety Warning! I got brass failure/head separation after only 3 loadings. Using the same load with Hornady brass, I have had absolutely no problems. The Hornady brass have been loaded 16-18 times! Buy Hornady and don't take a chance on getting injured with Norma brass.

[@outspokengenius]

I'm guessing you got a bad batch or there was some other issue. Norma is not known for making bad products. I personally use .338 Winchester brass as .358 Norma brass has been out of stock everywhere since I got my rifle, and the guys who are willing to sell there .358 brass want $1-$2 per case.

[@jimv.661]

I sent the cases back to Norma and they agreed there was something wrong with them but refused to replace. And, stopped answering my emails. The Hornady brass now has 24 firings on them with no signs of giving up. Norma is too expensive to take a chance on, especially when the heads are separating off the case.

[@Valient6]

Get yourself an induction heater coil and a laser thermometer. So you can get the science right.

[@north61]

You know I have a laser thermometer but never thought to use it. Good idea.