Help; Forming 308 norma brass

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phaxtris

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Help! I am trying to form 308 norma brass from a bunch of win mag brass i acquired, i dont know if i am missing something, i run the 300 win mag through my 308 norma fl size die, and at best i get mabye 30% of the cases acceptable, is there a trick i am missing ? methods i have tried....

lube cases (use tp to remove any excess from area that shoulder will be compressed to), lube inside of neck with graphite, run case through in one straight shot
---worst results---

lube cases (use tp to remove any excess from area that shoulder will be compressed to), lube inside of neck with graphite, run case through 'stepping' when the ram starts to feel pressure
---30-35% ok brass----

lube cases (use tp to remove any excess from area that shoulder will be compressed to), lube inside of neck with graphite, run case through 'stepping' then pulling out slightly on ever step when the ram starts to feel pressure
---best results, about 35% ok---

now i am considering an ok piece of brass to have 0 denting on the shoulder, i dont know if some denting is acceptable (will be formed properly on first shot ?), or is it normal to only get about 30% acceptable ?

or maybe there is a better way entirely ?
 
If you have problems resizing brass for your .308 NM, simply switch to 338 Win Mag brass.. down size the neck, push a primer in, fill with powder, top with a bullet and fire.
No need to trim or whatever, no need to turn the necks, nothing.
If you are not sure, just reduce your loads by 10% for fire forming, but a lot of use simply use our standard loads, as long as it's not a very hot one, it should do the trick.

The dents come from too much lube, to avoid it you may need to resize in more than one pass and whipe the brass and die in between. Try using sizing wax, it should help. But using .338 WM is much, much simpler.
 
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I'm going to borrow my buddies Bonanza dies and try some 300 win mag brass
with them.
I know these dies are just too darn easy to use on proper brass.
Might be worth a try other than my RCBS.
 
Are you removing the expander and rod for the first pass? Only lube the .300 win case up to where the 308 NM shoulder will be no higher.Easy on the lube to avoid oil dents.Inside necks with a Q-tip as well. Then trim to length reassemble die and run them through once more.Shouldn't lose any more.I use .300 win mag range brass once fired.Harold
 
i tried once removing the decaping rod, and couldnt run the brass through afterword with the rod in place, but i will give that a shot as well, i was only using graphite in the neck tho, i will try with actual lube, and just was the cases afterword
 
I have formed literally hundreds of 308 Norma Mag Brass from 300 Win Mag brass.
My losses usually amount to maybe 3% or less.

Keep excess lube off that case!!! As mbogo said, do NOT put any lube on the 300 case above where the new shoulder will be.
I lube the neck inside, but do not remove the expander button.

I have used RCBS, Forster and Redding dies with the same success.
New brass is the best, but 1-F works fine as well.

Don't bother with Federal brass, it's not worth the time spent, IMHO.

Regards, Eagleye.
 
It works a lot better if you move the shoulder back with a 338 WM die first, then through the 308 NM die and you won't lose any. The shoulder dents are also irrelevant, just load and fire them, they come out perfect, just no creases.
 
I just finished attempting this feat this weekend. I had 338 win mag brass, 7mm rem mag brass, 300 win mag and some factory 308 norma brass for comparison. The .338 brass was winchester stamped brass and the easiest to form but definitely comes up short in the neck, I had mixed results with the .300 win mag brass but had some federal, some remington and some winchester. All once fired from my dad's rifle. My best results were from the remington cases. The federal cases showed good results as well but the case volume was off from my factory norma brass. The winchester cases were once fired as well and they consistently creased and wrinkled in the shoulder no matter how much or little lube I used and even backed off the die to see the results. My only conclusion is that my winchester brass must be slightly harder and causing the wrinkles and creasing.

My remington brass, out of the 40 that I played with had 2 of them that creased or severely wrinkled the shoulder. My best results were achieved by trimming the cases closely to 2.56" in length and chamfer, I then lubed the case inside the neck and the body and put through the die with expander ball/decapper in. I then finished the final bit of trimming to 2.55" and chamfer. They cycle slicker than poo through a goose in my rifle and the shoulder barely makes contact in the chamber of my rifle when doing my checks.

I would imagine if the cases would be all new or annealed, they would all form quite easily with minimal wrinkles or creasing.

I would say that a small amount of wrinkles is acceptable, I was rejecting rounds that had anything more than minor wrinkles.

good luck.
 
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