375 H&H to 375 Weatherby fire forming

1

1972RedNeck

New member
Picked up a bunch of almost affordable of 375 H&H brass for my 375 Weatherby. I could load up some mild loads with cast bullets to fire form them, but I'm wondering if there is a cheaper option? I have heard about using pistol powders, corn meal, and cotton balls.

Any good recipes that will save me some money?
 
You do realize that what ever method you use, your formed cases are going to be a little short, right??
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Yes.

Or since all of my brass is H&H head stamped, maybe actual Weatherby brass is a little long...
 
maybe actual Weatherby brass is a little long...
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well, that's one way to look at it, :D

By the specs, Wby brass has a max length 0.01" longer than the .375 H&H, and forming WBY cases by blowing out the body of H&H brass is going to make them shorter, yet. How much, I can't say, never did it, but it will get shorter.

Shorter, in this case is better than thinner though. That much is certain.
 
1972RedNeck said:
I could load up some mild loads with cast bullets to fire form them,
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In my experience of fireforming wildcats that method will not work, the brass will not flow properly. What I learned is you'll need to create a false shoulder. You can do this by necking up one size, and then run your case back into a FL size die in small steps. You want your action to be slightly hard to close because you're jamming the shoulder against the chamber. Then most recommend when FF an Ackley Improved shoulder to use a max charge for bullet weight you're shooting. So that'll probably rule out cast bullets that aren't coated.

You'll also more than likely need to anneal your cases after FF. I actually had to anneal my cases before and after FF, because I was taking a .405 Win case down to 7mm with an 40⁰ shoulder. I ran the case trough three different dies (.35 Whelen, 8X57, and finally .280 GNR) to get a false shoulder and the neck down to 7mm.

I lost about 50% of my cases during the FF process until I started annealing before FF. I'd usually develop a crack in the neck. You anneal after FF because you're moving a lot of brass, and it makes it very hard.

In the end, I probably just should have purchased already formed brass from Gary Reeder. It was expensive, but it was probably cheaper in the long run than learning to FF brass correctly.

Here is some .375 Weatherby brass.
 
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