30 Herrett from 375 w cases

[WayneS]

Are there any additional steps in forming 30 Herrett brass from 375 W cases ? I plan to first run them through a 30-30 FL die ??

[Graybeard]

I'd not do that. What I would do is cut them close to proper length then run them into the .30 Herrett die and then do another trim to proper length. That way no fire forming should be needed. If you first run them into the .30-30 die fire forming will be require negating the advantage of using the more expensive .375 brass.

[banjoman]

If you decide to do that I got some 30-30 brass i would swap for your 375 brass.

[Lone Star]

Because .375 brass is considerably thicker than .30-30 brass, you will have to reduce the loads shown in the manuals or you will exceed recommended pressures. In truth there is no real advantage in using the .375 cases since .30-30 brass is plenty tough enough for the pressures encountered in the .30 Herrett.  I made one box of .375-based cases for one of my .30 Herretts, and that was enough!  I still have beaucoup .30-30-based Herrett cases that have been loaded over twenty times and they are still going strong.  The secret to long Herrett case life is not which brass you use, it is how you size the cases.  Top IHMSA shooters learned that decades ago...


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[WayneS]

Thank all for the advice, I've decided to save the 375 brass for a 30-30 AI  & 7-30 Waters project.
lone star, My IHMSA # of 566, The Herrett is a project for my grand son when he returns from Iraq.

[Reed1911]

I highly recommend annealing the portion you plan to neck down for either 303AI or 7-30W. Even doing so you'll loose about 5% of the cases, without annealing you are looking at about 20% loss.