reloading dies for 358 winchester

[Carphunter]

If I intend to make 358 winchester cases from 308 brass, do I have to use a full length sizer, or can I use a neck or neck bushing die for this process?

I'll be using ammo in a bolt gun, so I assume the fired brass should be ok only neck sized... but not sure that neck sizer will cut it for the initial expanding of the neck

[Graybeard]

I dunno either really and suspect you'll just have to give it a try and see if that's all you have. I'd use the FL die tho if you have it then switch to NS once you've fired it the first time. I've always used a FL die for case forming of that sort even when I have a NS die so just have no experience base to go on.

[blpenn66502]

You need to use a FL sizer so that you can push the shoulder back to the 358 Win spec so it headspaces properly.  A neck sizer isn't going to do that.

[cwlongshot]

I have done this as 358 brass is scarce. I agree with Bill & blpenn66502, YES, you must use a FL 358 die for forming. Then shoot them once in your rifle before using a neck sizing die. I like to use military brass as it will not have a caliber designation on the head.

BTW, One product I do like form LEE is there collet neck sizing dies. They work very well.

CW

[rickt300]

I sized 30-06 brass up to 35 Whelen using a 358 Winchester die set not to touch the shoulder and then used the same dies to load ammo with. This is 100% neck sized and it has worked perfectly for 300 shots or so out of the same 60 pieces of brass.

[cwlongshot]

I sized 30-06 brass up to 35 Whelen using a 358 Winchester die set not to touch the shoulder and then used the same dies to load ammo with. This is 100% neck sized and it has worked perfectly for 300 shots or so out of the same 60 pieces of brass.

I once ate spaghetti with a spoon too.      Then I discovered there was a correct way to eat spaghetti. 
 
 Why would you say such a thing? There are multiple ways to do everything, I don't think any of us meant to suggest otherwise. Not all are safe, not all smart, not all are correct. We have outlined the correct and acceptably way to reform a case to another caliber.
 
 BTW, some critical case dimensions for those two calibers are different, specifically the neck lengths. You would need to get the length set so as not to make too long or too short a neck. Your also not "100%" neck sizing, like you think. The 358 die is partially resizing as much as it can reach.
  Absolutely it can be done, your doing it. I am glad it has worked for you. But its certainly NOT the correct way to do this and not something for the inexperienced novist. You need to know exactly what your doing. It requires far more setup and accurate measuring to get it right. IMHO, it's FAR easier to screw the correct die in your press, until it touches the shell holder, lube up a case and push it in the die and remove a correctly sized case in a new caliber. No measuring, no guessing, no problems.

CW

[rickt300]

Actually it is not such a far out thing to accomplish and rather simple really.  Headspace for the 358 and the 308 are the same. It would stand to reason that the case shoulder, if left untouched would not be in some wildly wrong position in the universe.  It is the same for the 30-06 and the 35 Whelen. And yes there are limitations using the 358 dies, no I am not sizing all of the neck (The Whelen has a long neck) this is true. I would reccomend he start with new or once fired brass that will chamber in his rifle and lube the inside of the case neck with something very slick.  I use Armorall protectant Original, the stuff you might use to protect your cars dash with. Spray some on a patch, put the patch on your cleaning rod and coat the inside of the case neck with it. Doesn't have to be a heavy coat just even.  The nice thing about using this is that you don't have to remove it from the inside of the case neck after sizing.  I have recently used my 358 dies to load 35 Remington shells for my Contender, as a single shot pistol it needs no crimp and the length of the neck that is sized is ample to hold the rather short 200 grain RN's bullets I load in it.  I did this because Midway backordered the 35 Remington dies I wanted but now they have arrived and are much to be preferred as they size the body of the case and bullets can be crimped for my Marlin 336. And by the way, screwing the die into the press until it touches the shellholder IS NOT the way to set the headspace of a newly formed case. You are far better off setting the size die down in increments until the shoulder in the die barley touches the cases shoulder, then see if it will chamber in your rifle, if it will great, if not turn the die in another 1/4 turn and try again.  The variation in the shellholder where the case head bears upon and the face of the shellholder are seperated is often a lot and not kept to close enough tolerance to gaurantee proper headspacing. I would have to say that the common practice of using the face of the shellholder to headspace your cases for full length sizing has caused more case seperations and damaged brass than any other reason.  In fact learning to properly set your size die is one of the most important aspects of reloading.  I don't know what kind of neck sizers you are using but will say if it has a tapered expander button you can make it work.

[wncchester]

" BTW, some critical case dimensions for those two calibers are different, specifically the neck lengths."

Actually, the critical case dimensions are the same, that is the case length, the length to the shoulder and the shoulder angle are the same.  That means the neck length will automatically become the correct length for the .358, it just starts further up the shoulder slope. 

Anyone doing a case reforming job will greatly benefit from using an FL die (NOT just a neck die) when making the initial change.  Although there is no reshaping of the body in this change, as such, the pressures and tensions in changing the neck diameter is very likely to distort both the shoulder and neck to shoulder junctions that only a FL die can make correct.

I would prefer to make .358 cases from .30-06, sizing down has always worked to give me better necks in the finished product.  But neckin' up a smaller case will sure work too, if not quite as well.

[rickt300]

My 358 was headspaced at max Saami and it was best to not even touch the shoulder or I would get misfires using Winchester 358 brass for the first firing. Oddly I never had this problem when resizing 308 cases, I liked Federal brass best.  This is a great cartridge and I wish I still had my old model BLR.  I liked to set my die so that I could just barely feel some resistance when closing the action.

[wncchester]

"I liked to set my die so that I could just barely feel some resistance when closing the action."

That's exactly the way it should be done.

[Sweetwater]

Guess I sided with caution. I sized some 257Roberts to 8mmx57 and vice versa a whole lot of years ago - just because. I started with a 6.5x55 expander plug in my 8mmx57 sizing die. I then took a .308 expander plug and repeated the process. Final step with proper 8mm expander plug in 8mmx57 sizing die. Results were flawless, no annealing, no split necks, all went easy in the smaller steps. I did do some in one pass through the 8mmx57 sizing die, and got several split necks. So, I chose the slower path.

Always more than one way to do things.

Regards,
Sweetwater