Winchester 375 BRASS made from ???

b72471

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I realize this brass is available but I do from time to time form brass from other calibers. Sooo I was looking at this win 375 it appears it could be made from 38-55 or even 30-30 brass. The size appears correct but not sure of wall thinkness of the 30-30 case, will have to section and measure I guess.
Thanks.
 
.375 is heavier than 38-55 and related cases. It's a higher pressure round.

If you're making it from 38-55 I'd stick with 38-55 data
 
I used the COW method to make them into straight-walled cases. 10 grain of Bullseye, fill with Cream of Wheat, plug with a small wad of TP, and fire in the 375.
Voila! a 375 Case. :) I would lose the odd case to splits, but only about 1 in 30 or so, so felt the losses were tolerable. I annealed after fireforming.
Be careful, those thin cases are easy to over heat. Dave.
 
Thanks Dave. I've done the COW method for fire forming my new loose fitting .38-55 Starline brass. So I know the drill well.

One more request. Do you have a couple of these formed cases and could you measure the resulting mouth wall thickness for me?
 
The COW method of fire forming can be hazardous, be careful where you stand.

cow_zps8715d784.jpg
 
I have managed to open up the 30-30 necks using dies, I used the 350 mag die and then the 375 dies, passing the brass up through the expander only. If you have a 338 mag die you could include that. Remember to lube the inside of the necks.
Enjoy.
 
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Thanks Dave. I've done the COW method for fire forming my new loose fitting .38-55 Starline brass. So I know the drill well.

One more request. Do you have a couple of these formed cases and could you measure the resulting mouth wall thickness for me?

No problem at all!! I just measured up 2 - 375 Winchester original cases first. The wall thickness at the mouth of a fired case is: .0110"
I have several cases fire-formed from WW Super 30-30 cases, they measure: .0105"
I also have some formed from old Dominion 30-30 cases, and they measure: .0090" [These are the thinnest I have.]

So you can see, the difference is not particularly dramatic, even with the Dominion cases. Dave.
 
For me that's solid gold info even if it just saves me reforming something that won't work.

You see, I've got a rolling block .38-55 with a slightly too large chamber and a .376 groove diameter. If I load up my Starline .38-55 brass with the .008 to .009 wall it's really loose in the chamber. To give it a better fit I'm using some .375Win brass. But I don't have much of it. If I could fire form some .30-30 and keep something bigger than a .010 wall that would be a great way to add to my collection of "thick wall" brass to use in that rifle.

From what you say it'll depend on the wall thickness of the .30-30 I start with. I'll have to measure the stock of .30-30 I've got.

Thanks for taking the time and filling in another piece of the puzzle for me on that rifle.
 
You are fire forming in the rolling block. If you have the right expander you can expand the neck oversize to mate with the chamber neck then use the cow to form brass to chamber dimension.
Enjoy
 
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