Fireforming .308 to .358, what am I doing wrong? Problem solved 2 different ways

[smong2000]

Guys,

I did a bunch of reading and decided to save some $$ and do my fireforming with cornmeal instead of bullets.  Plenty of people wrote in various forums that 5 grains of Bullseye with 1/4 sheet of TP over it, then fill with cornmeal or cream of wheat and cap off with more TP does it pefectly.  Well not for me it didn't.    I got lots of attention at the range for my confetti loads but it hardly budged the neck of the case.
What am I missing?  More powder needed? Has anyone here actually done it successfully?
Thanks

[necchi]

but it hardly budged the neck of the case.

I don't think fire forming is/was ment too, or capable of, changing neck diameter that much, (from 308 to 358).

 It's usually just to push out the shoulder and body of the case to the current chamber or bump out an AI shoulder from a standard case.

[AtlLaw]

Hummm, 

I've made a LOT of 358's (and 338's) out of 308 brass and never felt the need to fireform them.     A full length die with a tapered expander always worked fine for me...   Am I missing something?

[smong2000]

Necchi,
I think you are right, looks like it will take a lot of pressure to blow out the necks.  I did a web search and there were 2-3 references to the recipe i used.  I have been just loading up junk bullets in the .308's and rattling them down the barrel.  Made beautiful cases that way but now I'll have to buy bullets so looking to save money.

AtLaw,
Tapered expander  do you have a part number or did you make your own?  I've been getting strangely shaped mouths when I sized with my Lee die, they always come out short and slanted even when I do the sizing in 2 or more steps with lots of lube and rotate them part way.  They seemed to work just fine and I got some great groups from them but it drove me nuts to look at them.  I even bought a bag of Win factory .358 brass and it really screwed me up with high pressure at reduced loads (1.5 grains). 
May I ask what rifle you are loading for and what kind of OALs are working?  My BLR is giving me 2550's and great accuracy with H322 and IMR 4064 but I'm right in the lands at 2.710 and the IMR is a compressed load at sub max.   

[Pop]

Why are you fireforming?  It is not needed.  All you need is a little lube in the neck and run them gently through the 358 expander.  Shoulder angle is the same.

[smong2000]

Pop,

I was trying to blow the neck out to .358 because my regularly expanded cases have slanted brass at the tops after sizing.  I just made up another 20 and really carefully loaded them to check accuracy and uniformity.  It may be purely cosmetic and I'm being too fussy.
Thanks,
Steve

[LaOtto222]

I believe that Hornady, for one, uses a tapered expander in their full length sizing dies. Use plenty of lube and have at it. You may have to trim after expanding up that far - maybe not. Good Luck and Good Shooting

[necchi]

Ya that's what I was thinking. Is the entire neck "slanted" or just the very top perimeter of the neck that needs to be trimmed?

If it's the later, I'd trim to at least get the neck even.

[smong2000]

The neck is parallel to the case but the tops are slanted.  Problem is that they get shorter than 2.005 so my trimmer doesn't touch them until they've been shot a few times. 

[stimpylu32]

The neck is parallel to the case but the tops are slanted.  Problem is that they get shorter than 2.005 so my trimmer doesn't touch them until they've been shot a few times. 

I take it your using a Lee trimmer ? If the kock-eyed case's are giving you groups that you can live with , then just wait till they grow long enough to trim , if not , then you may have to do a mod on the trimmer or buy a 2nd one and mod it to square up the case mouth .

stimpy

[smong2000]

Stimpy,
Yes, it's a Lee trimmer.  That's a good plan, I'll fire off these 10 and if they shoot right, I'm done.  I'll grab another pilot for my trimmer next week and set it up for 2.000" for my next batch.

[schoolmaster]

We are fireforming .25 WSSM cases to .358 WSSM. First the cases are annealed then primed, we use 10 grains of unique, then cream of wheat filled to neck then tp to hold it in. Fire formed 100 out of 100 this way. When we skipped the annealing process, we lost 14 out 100 with split necks.

[smong2000]

Schoolmaster,

So you are actually blowing out the .25" necks to .358 just with 10 grains of Unique?  I gotta up my load and try it again.  I think 10 grains of Bullseye would be a safe bet.  Fireforming makes the prettiest cases...and I feel good using them the 1st loading in the larger caliber. When I was fireforming with regular .308 loads and bullets, I had no case splitting even on some older (4-6X loaded in .308) brass.  I used Federal which seems much softer than Win or RP and is giving me more than 10 loadings in my .270, in fact I stopped counting on my practice stuff. My .358 FC doesn't hold up quite so well, I'm tossing it after 4-5 loads - gets pretty thin in the neck.   
 Are you getting decent neck tension on that brass?? Or crimping?

[Win 1917]

If your dies don't have tapered exapnder buttons go to C&H dies and look at their tapered expanders. They're resonably priced and you specify whatever beginning and finished size you want. The exapander screws into you existing dies.

[Pop]

Honestly the only dies I have used for my BLR 358 in the past were the RCBS and the Redding.  Both only took one pass with some lube inside /outsidethe neck and they were done.  I had Lee make me a special Lee case length gauge and that is how I trip them.  
I had lee make them for all my oddballs.  378 WBY 416 WBY, 375 Snipetac, 356 Win, 223 wssm (when it was new)  etc.  Give them the dimensions and a week later you get it in the mail.

[schoolmaster]

2000, yes 10 grains of unique, then poured the cream of wheat on top then a wad of tp. Was careful not to shake them up and held the rifle upright to load and fire. These cases then needed to be trimmed, sized and the necks were turned with a forster outside neck turner. The bullets have good neck tension and have no crimp. I am shooting Barnes bullets and they are tight. 10 grains of bullseye should do it the trick is to fill the rest of the case with cream of wheat to provide resistance and up the pressure for good fireforming. We tried cornmeal but the cream of wheat was better.

[smong2000]

Well I got creative, chucked my expander in a drill and put a good taper on it and polished it.  WOW!!!  What a difference that made.  I am now getting perfect brass with very little effort.  Just for grins I ran some 7-08 brass through and it was hard to squeeze up but came out perfect.  I tried 3 different lubes and the Lee waxy stuff worked best.
Thanks for all the info gentlemen, I learned a lot.
smon2000   

[smong2000]

As a follow-up I will report that 10 grains of Bullseye with cornmeal to the neck and a TP plug makes perfectly fireformed .358 win brass from .308 brass.  And the slant topped brass I made with my homemade tapered expander shot bug holes at 50 yds and chronied 2514, 2516, 2517 for one load and 2547, 2547, 2549 for the other I tested proving to me that it's purely cosmetic.    It was a good range day. 

[Dinny]

As a follow-up I will report that 10 grains of Bullseye with cornmeal to the neck and a TP plug makes perfectly fireformed .358 win brass from .308 brass.  And the slant topped brass I made with my homemade tapered expander shot bug holes at 50 yds and chronied 2514, 2516, 2517 for one load and 2547, 2547, 2549 for the other I tested proving to me that it's purely cosmetic.    It was a good range day. 

I just loaded up some myself. I got some .358 Win brass that was necked down to .308 and now they're on their way back to .358. I'm glad my RCBS Chargemaster keeps track of how many charges it throws. I thought I double-charged one and kept it to the side. After I was done with my 20rd batch, the Chargemaster read 21. I pulled it apart and reloaded with 10gr. Life is good.


Thanks for the advice, Dinny