Reforming 308win (and 7.62nato) brass to 358win

[JonB_in_Glencoe]

I have a scant few pcs of brass with HS of 358win.

I made a couple attempts at reforming some 308 and 7.62
They are coming up short...is that to be expected ?
should I be annealing them ?

The few I tried didn't crack, but will annealing them keep them from shortening or will the softer necks actually shorten more ?

my first attempts where using FL sizer die expander spuds in 3 steps,
338, then 348, then to 358

Then I remembered I had made some custom Neck expander spuds I made for the lee universal flare die. I have one that is an actual .357 that has a long gradual nose...that worked slick...but still came up short in length.

Any comments ?
thanks

[JonB_in_Glencoe]

I think I posted this in the wrong area ?

[geargnasher]

Try using .30-'06 brass next time. Knock back the shoulder in a .308 die, whack it off a tad long, do your expanding mojo like above, trim to length, and outside turn to precisely fit your chamber neck clearances. I do this for several calibers without annealing as I prefer the hard necks made from shoulder material. The extra thickness is very handy, too.

Gear

[geargnasher]

One more tip, but it probably WILL require annealing: Get some fired NATO blanks made in this century. The necks are extra-thick and extra-long, will require cutting same as '06 in a trim die or with a homemade jig and chop saw. There may be way too much material there to turn down to fit your chamber, but that can be a good thing rather than the usual situation that is reversed.

Gear

[barkerwc4362]

Almost all of my 358 came from mini-gun fired 7.62x51 brass. I just neck up and then anneal the necks to keep them from splitting on the second firing. They may be a little short, but they will grow. I form 375 Whelen Improved from 35 Whelen brass and it comes up a little short, but not enough to matter. We are not talking about small caliber bench rest rifles here. When I do my part my 358 will put five 250 gr Hornady RN into an inch at 100 yards. Mine is a custom 20" Douglas barreled commercial Mauser actioned rifle. It is my "Black Rifle". Matt blue and black composite stock. Leupold 1x4 VarX-ll on quick detach mounts. New England Custom Gun Service banded front sight and receiver rear sight.

Bill

[Sweetpea]

Jon, what length are they starting out at, and what length are they ending up at?

I was working on some 7.62 brass several days ago, and before it was sized, they were running around 2.035...

[JonB_in_Glencoe]

Gear, I don't have neck turning tools...I guess I could remedy that easy enough.

Sweetpea, I didn't measure them before...I found a baggie of about 20 "WCC" that I forgot about, I think I picked it up at a gunshow, baggie said $1. After sizing up, they are 1.995 to 2.000"

I was just reading another thread about this, and I remember I have another baggie somewhere with some 7.62 nato ammo. I'm considering shooting it to fireform.

[Pilgrim]

Guess I'm too dumb to worry about that reduction in length! I simply run the .308 / 7.62 brass into my RCBS FL sizer and voila! I have .358 cases. I load 'em and fire 'em. No biggy as near as I can tell. FWIW...Pilgrim

[RustyReel]

Guess I'm too dumb to worry about that reduction in length! I simply run the .308 / 7.62 brass into my RCBS FL sizer and voila! I have .358 cases. I load 'em and fire 'em. No biggy as near as I can tell. FWIW...Pilgrim

Me too!

[geargnasher]

"It only matters if it does" as Bass used to say. I assumed it mattered for some reason so I offered the solutions I know of. Maybe a solution looking for a problem unless paper-patching, only Jon can say in his case.

Sometimes, fireforming shrinks the brass even more, so forming maximum-length cartridges is in order on the first go and then trimming for a uniform, safe clearance after that. It all depends on how you do things.

Gear

[JonB_in_Glencoe]

"It only matters if it does" as Bass used to say. I assumed it mattered for some reason so I offered the solutions I know of. Maybe a solution looking for a problem unless paper-patching, only Jon can say in his case.

Sometimes, fireforming shrinks the brass even more, so forming maximum-length cartridges is in order on the first go and then trimming for a uniform, safe clearance after that. It all depends on how you do things.

Gear
Well, it matters to a point. I'm not sure where that point it yet ;)
Gear, your solutions are MUCH appreciated.

I was hoping fireforming (shooting the 7.62 ammo in the 358 gun) would be more uniform than using dies and less chance of shrinkage. I wasn't impressed with the few WCC that I did, I got a small donut at the base of the neck on a couple(I've read about that and pressure and may reject those).

I haven't found that baggie of ammo, so I don't know if it's matching HS or not? or even US or Foreign? Berdan ? Road trip today, so I won't get back to the reloading bench til evening.