.458 Sizing issues..The plot thickens...

[jeeptim]

Happy new year!!!
As some of may know I have been having issues with 458 Socom brass not fully sizing around the base of the case.... trouble chambering and ejecting.
So sent brass to starline they say yes not sizing at base this is like 50 out of 300 they say it's my sizing die.
Now I checked with a Lyman ammo checker multi caliber.
So I buy a Lyman small base die set came with an ammo checker.
This is the weird part........
The oversized cases checked with calipers they ARE oversized by as much as 10 thousands fit In the ammo checker that came with the die set but not in the multi caliber Lyman ammo checker.
I ran some over sized cases through the small base die and all good to go.
In a nutshell.. The lee sizing die dose not size the widest part of the case near the head.
The Lyman small base die seems to have fixed me up.
The Lyman multi caliber ammo checker is awesome.
The Lyman single .458 Socom ammo checker is...... I hate to say junk but it's letting a case 10 thousands over sized freely fit and 100% will not work.
At the end of the day and it was a long long day looks like I'm back in business. Took about a month to get the die set. Backordered.
The shining point in this story was how well I was treated by Starline.
He measured and sized every case several very kind emails and replaced the brass I sent with twice as much new.
And I tell you the members of the high are a wealth of information!!
And much of the information and the way we share it comes from our dear departed friend R.C. Model.
Rest in peace my friend!!
God Bless!!
And Thank you All!!

 

[243winxb]

Looks like the 458 Socom is not a SAAMI approved cartridge. No standard has been set.

Wildcat cartridges may have these problems.

Looks like your have found the fix. Good job.

 

[jeeptim]

I think your right!!
Even the same company is not consistent.

 

[Blue68f100]

Yes, That is why I went with with Redding dies. They were the only ones reported of not having any problems when I got into the SOCOM 3 yrs ago. I also got the upper from Tromix which were the developers of this round. So I knew I had a in spec chamber. The are licensed by Sheridan to make the case gauges for this caliber too. So the gauges are made from the drop offs from their barrels. Which makes them pretty accurate.

 

[Kaldor]

Looks like the 458 Socom is not a SAAMI approved cartridge. No standard has been set.

Wildcat cartridges may have these problems.

Looks like your have found the fix. Good job.

458 is hardly a wildcat. Marty ter Weeme of Teppo Jutsu designed the cartridge in 2000 and Tony Rumore of Tromix was contracted to build the first .458 SOCOM rifle in February 2001. SAAMI just has been sitting on this one forever. Most figure its because Tromix isnt one of the big boys on the block. The shooting industry is small enough to know who builds what, and their customers are more than happy, so they dont push for it.

Most of the issues you see with people having are those that are using knock offs made without a licensed reamer. I have never heard of anyone having any issues with a Tromix barrel and bolt, or a barrel made with a licensed reamer.

This thread of the 458 SOCOM forums is worth a look: http://458socomforums.com/index.php?topic=2296.0